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Penguins: Promoting Polar Awareness While Melting Our Hearts
(Released August 2012)

 
  by Natalie Abram  

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Threats
  1. The complete phylogeny of Pseudobulweria, the most endangered seabird genus: systematics, species status and conservation implications

    Benoit Gangloff, Hadoram Shirihai, Dick Watling, et al.

    Conservation Genetics, Vol. 13, No. 1, Feb 2012, pp. 39-52.

    Pseudobulweria is one of the least known and most endangered of all seabird genera. It comprises six taxa, of which two are extinct, three are critically endangered and one is near threatened. Phylogenetic relationships between these taxa and position of the genus in the Order Procellariiformes have never been studied, and the taxonomic status of several taxa remains unsettled. Conservation management of Pseudobulweria taxa will be enhanced if these uncertainties are resolved. We used a multilocus gene tree approach with two mitochondrial DNA markers (cytochrome oxidase subunit 1 and cytochrome b gene) and one nuclear intron ( beta Fibrinogen intron 7) to investigate phylogenetic relationships within the genus using sequences from all taxa. We combined gene trees to estimate a phylogeny of the genus using a multispecies coalescent methodology. We confirmed the link between Pseudobulweria and a clade comprising Puffinus and Bulweria genera. The Fiji petrel's status, as belonging to the genus, is confirmed, as is the specific status of newly rediscovered Beck's petrel. Maintenance of the two sub-species of Tahiti petrel as currently described is not supported. Discovering the breeding grounds of all taxa is the key for their conservation, which is vital to both the marine and fragile insular tropical ecosystems where Pseudobulweria are apical predators.

  2. Salps in the Lazarev Sea, Southern Ocean: II. Biochemical composition and potential prey value

    C. D. Dubischar, E. A. Pakhomov, L. von Harbou, B. P. Hunt, V. and U. V. Bathmann.

    Marine Biology, Vol. 159, No. 1, Jan 2012, pp. 15-24.

    Two species of salps, Salpa thompsoni and Ihlea racovitzai, were sampled during three cruises to the Lazarev Sea, Southern Ocean, in summer (December-January) 2005/2006, Autumn (April-May) 2004 and Winter (July-August) 2006. Dry weight, carbon, nitrogen, protein, lipid and carbohydrate contents were measured to characterize the potential value of salps as a food source for predators in the Antarctic ecosystem. Biochemical composition measurements showed that despite having a high percentage of water (~94% of wet weight), both species had relatively high carbon and protein contents in their remaining dry weight (DW). In particular I. racovitzai showed high carbon (up to 22% of DW) and protein (up to 32% of DW) values during all seasons sampled, compared to lower values for S. thompsoni (carbon content only about 15% of the DW, protein content about 10% of the DW). At the same time, carbohydrates (CH) and lipids (Lip) only accounted for a small portion of salp DW in both species (1.4% CH and 3.6% Lip for I. racovitzai; 2.1% CH and 2.9% Lip for S. thompsoni). There was little variability in the biochemical composition of either salp species between the seasons sampled. Both biochemical composition and life cycle characteristics suggest that Antarctic salps, especially I. racovitzai, may be important prey items for both cold and warm-blooded predators in an environment where food is often very scarce.[PUBLICATION ABSTRACT]

  3. Aspects of Diversity in Early Antarctic Penguins

    Piotr Jadwiszczak and Thomas Moors.

    Acta Palaeontologica Polonica, Vol. 56, No. 2, Jun 2011, pp. 269-277.

    Penguin bones from the Eocene La Meseta Formation (Seymour Island, Antarctic Peninsula) constitute the only extensive fossil record of Antarctic Sphenisciformes. Here, we synonymize some of the recognized genera (Anthropornis with Orthopteryx, Delphinornis with Ichtyopteryx) and species (Anthropornis nordenskjoeldi with Orthopteryx gigas, Delphinornis gracilis with Ichtyopteryx gracilis). Moreover, we suggest that Antarctic species of Anthropornis and Palaeeudyptes, so-called giant penguins, may in fact comprise only one species each instead of two, based on evidence of well-marked sexual dimorphism. We also present new estimates of body mass based on femora testifying to the impressive scope of interspecific body-size variation in Eocene Antarctic penguins.

  4. Diversidad de aves y mamiferos marinos en bahia San Pedro, costa de Purranque, centro-sur de Chile/Diversity of seabirds and marine mammals in bahia San Pedro, Purranque coast, southcentral Chile

    Jaime A. Cursach, Jaime R. Rau, Jaime Ojeda, et al.

    Gayana, Vol. 75, No. 2, 2011, pp. 146.

    Between 2007 and 2009, we studied the diversity of seabirds and marine mammals inhabiting San Pedro Bay (Purranque, coastal area of the Osorno province). We assessed composition, diversity and abundance of these vertebrates that included 18 species of seabirds, with Spheniscus magellanicus and Puffinus griseus as the most abundant. Two species of penguin, a gull and a tern breed in the area. Marine mammal assemblages were composed of seven species, from which Otaria flavescens and Lagenorhynchus australis were the most abundant. A species of sea lion and an otter breed in the area. These results show the potential of this area for biological conservation and the development of special interest tourism initiatives, which promote conservation. Based on this information, we recommend establishing long-term study programs that will provide guidance to the local community, in terms of planning, regulation and assessment of tourism activities that can be developed.

  5. Effect of water-loving bird colonies on zooplankton in littoral zones of water bodies of different types

    A. V. Krylov, D. V. Kulakov and V. G. Papchenkov.

    Russian Journal of Ecology, Vol. 42, No. 6, Nov 2011, pp. 518-524.

    Changes in zooplankton developing under the effect of waste products from water-loving bird colonies were studied in water bodies of different types. The trophic status index in the nesting area showed no difference from its background values in an oligomesotrophic water body but was decreased in mesoeutrophic and eutrophic-hypertrophic water bodies. The abundance and biomass of zooplankton in the oligomesotrophic and mesoeutrophic water bodies were consistently higher than background values, while in the eutrophichypertrophic water body they were higher only at the beginning and in the middle of the nesting period. Irrespective of the trophic state of water body, the species diversity of zooplankton in the zone of impact from bird colonies was increased, but the number of dominant species remained unchanged, and no mass development of species indicating high organic load was observed; the proportion of Rotifera in the total abundance and biomass of zooplankton was decreased, that of Copepoda was increased, and the abundance of Cladocera was found to increase with the degree of overgrowing. Among possible explanations, this specific response of zooplankton is most likely due to changes in the ratio of nitrogen and phosphorus in the water.[PUBLICATION ABSTRACT]

  6. Seasonal Changes in Recruitment of Pteria penguin in North Queensland, Australia

    Michael Milione and Paul Southgate.

    Journal of Shellfish Research, Vol. 30, No. 1, Apr 2011, pp. 89-94.

    Spat recruitment of the winged pearl oyster Pteria penguin, in relation to season, substrate type, and depth was investigated at Orpheus Island in north Queensland for 27 mo, from February 2008 to April 2010. Two substrate types (70% shade cloth and open-weave polypropylene mesh bags) were deployed at 2 depths (4 m and 6 m) and checked every 6 wk for 3 spawning seasons to determine any differences in quantity of spatfall between these factors. No significant difference was found in spat recruitment between substrate types (P = 0.158) or depth (P = 0.349), although there was a significant seasonal effect on spat recruitment (P < 0.001), with a peak in the quantity of spatfall in late summer, from February to March, and no spat collected in the winter to spring (July to October). Maximum settlement of spat was 10.2 spat per mesh bag collector in February 2008. Recruitment was significantly reduced (P < 0.001) during the 2010 spawning season as a result of disturbance from severe storms generated by tropical cyclone Olga in late January.

  7. The Basal Penguin (Aves: Sphenisciformes) Perudyptes devriesi and a Phylogenetic Evaluation of the Penguin Fossil Record

    Daniel T. Ksepka and Julia A. Clarke.

    Bulletin of the American Museum of Natural History, New York, Vol. 337, No. 1, Jun 3, 2010, pp. 1-77.

    We present the first detailed description of Perudyptes devriesi, a basal penguin from the middle Eocene (~42Ma) Paracas Formation of Peru, and a new analysis of all published extinct penguin species as well as controversial fragmentary specimens. The Perudyptes devriesi holotype includes key regions of the skull and significant postcranial material, thus helping to fill a major phylogenetic and stratigraphic (~20 million year) gap between the earliest fossil penguins (Waimanu manneringi and Waimanu tuatahi, ~58-61.6Ma) and the next oldest partial skeletons. Perudyptes devriesi is diagnosable by five autapomorphies: (1) an anteroventrally directed postorbital process, (2) marked anterior expansion of the parasphenoid rostrum, (3) posterior trochlear ridge of the humerus projecting distal to the middle trochlear ridge and conformed as a large, broadly curved surface, (4) convex articular surface for the antitrochanter of the femur, and (5) extremely weak anterior projection of the lateral condyle of the tibiotarsus. The skull of Perudyptes is characterized by deep temporal fossae and an elongate, narrow beak that differs from other reported stem penguins in its short mandibular symphysis. The wing skeleton of Perudyptes preserves a combination of plesiomorphic features also observed in the basal penguin Waimanu and derived features shared with more crownward penguins. Features of the wing optimized as primitive for Sphenisciformes include retention of a discrete dorsal supracondylar tubercle on the humerus and presence of a modestly projected pisiform process on the carpometacarpus. Derived features present in Perudyptes and all more crownward penguins, but absent in Waimanu, include a more flattened humerus, development of a trochlea for the tendon of m. scapulotriceps at the distal end of the humerus, and bowing of the anterior face of the carpometacarpus.

  8. Behavioural switching in a central place forager: patterns of diving behaviour in the macaroni penguin (Eudyptes chrysolophus)

    Tom Hart, Richard Mann, Tim Coulson, Nathalie Pettorelli and Phil Trathan.

    Marine Biology, Vol. 157, No. 7, Jul 2010, pp. 1543-1553.

    Recording the activity of animals as they migrate or forage has proven hugely advantageous to understanding how animals use their environment. Where animals cannot be directly observed, the problem remains of how to identify distinct behaviours that represent an animal's decision-making process. An excellent example of this problem is that of foraging penguins, which travel to sea to find prey to provision their young. Without direct sampling of the prey field, we cannot calibrate patterns of movement with prey capture, and therefore we cannot determine how different activities link to decision-making. To overcome this, we use a hidden markov model (HMM), which is a machine-learning technique that seeks to identify the underlying states of a system from observable outputs. We apply HMM to determine classes of behaviour from repetitive dives. We take dive data from 103 breeding macaroni penguins at Bird Island, South Georgia, for which we have measures of weight gain over a trip. We identify two classes of behaviour; those of short-shallow and long-deep dives. Using these two behaviours, we calculate the transition probabilities between these states and analyse these data to determine what predicts variation in the transition probabilities. We found that the stage of reproduction during a season, the sex and year of an individual influenced the probability of transition between long-deep and short-shallow sequential dives. We also found differences in the hourly transition rates between the four reproductive stages (incubation, broodguard, crèche and premoult) over a daily cycle. We conclude that this application of HMMs for behavioural switching is potentially useful for other species and other types of recorded behaviour. [PUBLICATION ABSTRACT]

  9. Do penguins dare to walk at night? Visual cues influence king penguin colony arrivals and departures

    Anna P. Nesterova, Céline Le Bohec, David Beaune, Emeline Pettex, Yvon Le Maho and Francesco Bonadonna.

    Behavioral Ecology and Sociobiology, Vol. 64, No. 7, Jul 2010, pp. 1145-1156.

    Orientation based on visual cues can be extremely difficult in crowded bird colonies due to the presence of many individuals. We studied king penguins (Aptenodytes patagonicus) that live in dense colonies and are constantly faced with such problems. Our aims were to describe adult penguin homing paths on land and to test whether visual cues are important for their orientation in the colony. We also tested the hypothesis that older penguins should be better able to cope with limited visual cues due to their greater experience. We collected and examined GPS paths of homing penguins. In addition, we analyzed 8 months of penguin arrivals to and departures from the colony using data from an automatic identification system. We found that birds rearing chicks did not minimize their traveling time on land and did not proceed to their young (located in crèches) along straight paths. Moreover, breeding birds' arrivals and departures were affected by the time of day and luminosity levels. Our data suggest that king penguins prefer to move in and out of the colony when visual cues are available. Still, they are capable of navigating even in complete darkness, and this ability seems to develop over the years, with older breeding birds more likely to move through the colony at nighttime luminosity levels. This study is the first step in unveiling the mysteries of king penguin orientation on land.[PUBLICATION ABSTRACT]

  10. Fine scale biologging of an inshore marine animal

    Tiana J. {a} Preston, Andre Chiaradia, Sherrie A. Caarels and Richard D. Reina.

    Journal of experimental marine biology and ecology, Vol. 390, No. 2, 2010, pp. 196-202.

    We compared the results of two biologging techniques used to study the foraging behaviour of a colony of small inshore predators, little penguins (Eudyprula minor). The first technique involved the use of satellite transmitters and diving loggers deployed on separate individuals, which has been the conventional method of tracking the movements and behaviour of this species for >10 years. The second technique combined a diving logger and a global positioning system (GPS) logger deployed on the same individual, which is similar to the biologging methods presently being developed and used for many other species. We then considered the value of each technique as a conservation tool operating at the small scale (foraging area <5000 ha and duration <1 day). We found that the separately deployed satellite transmitters significantly underestimated the penguins' foraging area size. However, the size of the foraging area and other foraging parameters, such as total distance travelled, were influenced by the degree of GPS location sub-sampling. Furthermore, only the combined diving and GPS loggers could confidently describe the diving behaviour of the penguins in relation to the sea floor and identify that they were using small areas of conservation interest (shipping channel) inside their foraging area. Hence, the method employed to assess habitat use at fine scales can influence conservation measures that rely upon the data collected. We suggest that researchers fast-track their adoption of high resolution multi-loggers for increased data confidence when tracking animals at a fine scale, but also consider the potential effect of sampling rate on the calculation of parameters of interest. Crown Copyright [copyright] 2010 Published by Elsevier B.V. All rights reserved.

  11. The history of the discovery of emperor penguin colonies, 1902-2004

    Barbara Wienecke.

    Polar Record, Vol. 46, No. 3, Jul 2010, pp. 271-276.

    This article summarises the history of the discovery of emperor penguin Aptenodytes forsteri colonies. Emperor penguins were probably first seen on James Cook's second voyage (1773-1775) but were not recorded as a separate species until 1844. The first breeding colony of these birds was found in 1902 and a further 32 were sighted over the next century. The total number of colonies is still unknown but today satellite technology is aiding the process of discovery.

  12. The structural mechanics and evolution of aquaflying birds

    Michael Habib.

    Biological Journal of the Linnean Society, Vol. 99, No. 4, Apr 2010, pp. 687-698.

    Mass-specific bone strength was examined in the forelimb and hindlimb of 64 species of birds to determine if aquaflying birds (which utilize the wings for propulsion underwater) differ in their skeletal strength compared with other avian taxa. Long bone strengths were estimated from cross-sectional measurements. Compared with the expectation from geometric similarity, humeral section modulus in volant birds scales nearly isometrically, while femoral strength scales with significant positive allometry. Penguin mass-specific humeral strength is greatly elevated, but the average humeral strength in species that are propelled by the wings in both air and water do not differ from the values calculated in non-diving taxa. However, amphibious flyers have gracile femora. Comparative analyses using independent contrasts were utilized to examine the impact of phylogenetic signal. The residual measured for the penguin-procellariiform humeral strength contrast was larger in magnitude (residual of 2.14) than at any other node in the phylogeny. The data strongly indicate that the transition from an amphibious flight condition to a fully aquatic condition involves greater changes in mechanical factors than the transition from purely aerial locomotion to amphibious wing use. There remains the possibility that a historical effect, such as ancestral body size, has impacted the mechanical scaling of penguins. [copy ] 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 687-698.

  13. Following the fish: penguins and productivity in the South Atlantic

    P. D. Boersma, G. A. Rebstock, E. Frere and SE Moore.

    Ecological Monographs, Vol. 79, No. 1, Feb 2009, pp. 59-76.

    We tested four predictions for central-place foragers provisioning offspring along a gradient in primary production spanning 1000 km of coastline in Argentina, using male Magellanic Penguins (Spheniscus magellanicus). Three of the predictions were supported. (1) Foraging trip distances corresponded with the production gradient; penguins swam shorter distances (mean maximum distance: 60-110 km) at the southern colonies where production is higher and prey species aggregate nearshore, and longer distances (143-242 km) at the northern colonies where production is lower and prey species aggregate at offshore fronts. Within these broad regions, foraging locations coincided with tidal mixing fronts or high chlorophyll concentrations. (2) Foraging trips followed a pattern of intermediate speed and meandering when outbound (32% of locations at sea), slow meandering movements within the foraging areas (45%), and very fast and direct returns to the colony (23%). Regardless of how far they went, penguins spent the most time at the outer limits of their trips, and travel speed slowed there, consistent with foraging. In 54% of trips, penguins left foraging patches between 15:00 and 21:00 hours, presumably with full loads for chicks. Returning penguins swam up to 173 km/d (2 m/s), swimming day and night and arriving at all hours to feed chicks. (3) Penguins stayed longer in more distant than closer foraging areas, presumably to feed themselves to recover the increased cost of swimming. One prediction was not supported. (4) Following a long trip, penguins did not meander more on their next outbound trip. Most penguins returned repeatedly to the same area to forage or alternated between two areas. Overall, penguin foraging patterns reflected patterns of oceanographic production, making them important sentinels of environmental variation.

  14. Gastrointestinal Obstruction in Penguin Chicks

    David Perpinan and Thomas G. Curro.

    Journal of Avian Medicine and Surgery, Vol. 23, No. 4, Dec 2009, pp. 290-293.

    A 7-day-old gentoo penguin (Pygoscelis papua) was found dead and postmortem examination revealed impaction of the ventriculus with feathers. A review of mortality in gentoo penguin chicks from 1997 to 2007 at that institution revealed another case of feather impaction of the ventriculus in a 4-week-old chick, a sibling of the previous chick. A third case of gastrointestinal impaction occurred in a 24-day-old king penguin (Aptenodytes patagonicus) with omphallitis and enteritis. In this chick, a fibrin mat produced a complete obstruction of the intestine at the level of Meckel's diverticulum.

  15. Nonlinear effects of winter sea ice on the survival probabilities of Adélie penguins

    Tosca Ballerini, Giacomo Tavecchia, Silvia Olmastroni, Francesco Pezzo and Silvano Focardi.

    Oecologia, Vol. 161, No. 2, Aug 2009, pp. 253-65.

    The population dynamics of Antarctic seabirds are influenced by variations in winter sea ice extent and persistence; however, the type of relationship differs according to the region and the demographic parameter considered. We used annual presence/absence data obtained from 1,138 individually marked birds to study the influence of environmental and individual characteristics on the survival of Adélie penguins Pygoscelis adeliae at Edmonson Point (Ross Sea, Antarctica) between 1994 and 2005. About 25% of 600 birds marked as chicks were reobserved at the natal colony. The capture and survival rates of Adélie penguins at this colony increased with the age of individuals, and five age classes were identified for both parameters. Mean adult survival was 0.85 (SE = 0.01), and no effect of sex on survival was evident. Breeding propensity, as measured by adult capture rates, was close to one, indicating a constant breeding effort through time. Temporal variations in survival were best explained by a quadratic relationship with winter sea ice extent anomalies in the Ross Sea, suggesting that for this region optimal conditions are intermediate between too much and too little winter sea ice. This is likely the result of a balance between suitable wintering habitat and food availability. Survival rates were not correlated with the Southern Oscillation Index. Low adult survival after a season characterized by severe environmental conditions at breeding but favorable conditions during winter suggested an additional mortality mediated by the reproductive effort. Adélie penguins are sensitive indicators of environmental changes in the Antarctic, and the results from this study provide insights into regional responses of this species to variability in winter sea ice habitat.

  16. Penguin population dynamics for the past 8500 years at Gardner Island, Vestfold Hills

    Tao Huang, Liguang Sun, Yuhong Wang, Xiaodong Liu and Renbin Zhu.

    Antarctic Science, Vol. 21, No. 6, Dec 2009, pp. 571-578.

    In order to reconstruct past changes in penguin populations we performed geochemical analyses on a penguin ornithogenic sediment core DG4 retrieved from a lake catchment on Gardner Island, Vestfold Hills. P, Se, F, S, As, Sr and Cu in DG4 were identified as the bio-element assemblage by R-clustering analyses on the elemental concentrations and comparisons with those in bedrock and fresh penguin guano. Factor analysis on the levels of these bio-elements in the core permitted a reconstruction of variations in historical penguin populations at Gardner Island spanning the past 8500 years. The penguin population showed significant fluctuations, reaching its highest density between 4700-2400 calibrated years before present. This coincides with evidence for a late Holocene warm period in the Vestfold Hills, similar to that associated with the late Holocene penguin optimum recorded in the Ross Sea and Antarctic Peninsula regions.

  17. Sex-specific parental strategies according to the sex of offspring in the Adélie penguin

    Beaulieu, Thierry, Thierry Raclot, et al.

    Behavioral Ecology, Vol. 20, No. 4, Jul/Aug 2009, pp. 878-883.

    In sexually dimorphic species, the sex of the offspring may induce different constraints for parents. At the same time, within pairs, males and females may have conflicting optimal reproductive strategies. As a result, they may adjust their level of parental investment differently according to the sex of the young. In this study, we examined whether Adélie penguin (Pygoscelis adeliae) chicks were sexually dimorphic and whether parents adjusted their parental investment accordingly. Male chicks were on average approximately 10% heavier than female chicks but not larger. Despite the presumed additional cost associated with male chick growth, no fitness cost differences were observed between parents rearing 1 chick whatever its sex: Adult body mass changes and resight rates during the subsequent breeding season were similar. However, the sex of offspring affected the duration of foraging trips during the early guard stage: At this stage, female adults rearing a female chick performed longer foraging trips than female adults rearing a male chick and males rearing either a male or a female chick. We propose that, because female adults present a lower survival rate after a breeding attempt, they are more prone to modify their level of parental investment than male adults. Moreover, the modulation of the foraging behavior by female adults according to the sex of the chick is likely to reduce intraspecific competition at a time when resource availability at sea is not optimal and when food requirement for female chicks may be lower than for male chicks.

  18. Where do penguins go during the inter-breeding period? Using geolocation to track the winter dispersion of the macaroni penguin

    C. A. CA Bost, J. B. JB Thiebot, D. D. Pinaud, Y. Y. Cherel and P. N. PN Trathan.

    Biology letters, Vol. 5, No. 4, August 23, 2009, pp. 473-476.

    Although penguins are key marine predators from the Southern Ocean, their migratory behaviour during the inter-nesting period remains widely unknown. Here, we report for the first time, to our knowledge, the winter foraging movements and feeding habits of a penguin species by using geolocation sensors fitted on penguins with a new attachment method. We focused on the macaroni penguin Eudyptes chrysolophus at Kerguelen, the single largest consumer of marine prey among all seabirds. Overall, macaroni penguins performed very long winter trips, remaining at sea during approximately six months within the limits of the Southern Ocean. They departed from Kerguelen in an eastward direction and distributed widely, over more than 3.10(6) km(2). The penguins spent most of their time in a previously unrecognized foraging area, i.e. a narrow latitudinal band (47-49 degrees S) within the central Indian Ocean (70-110 degrees E), corresponding oceanographically to the Polar Frontal Zone. There, their blood isotopic niche indicated that macaroni penguins preyed mainly upon crustaceans, but not on Antarctic krill Euphausia superba, which does not occur at these northern latitudes. Such winter information is a crucial step for a better integrative approach for the conservation of this species whose world population is known to be declining.

  19. Detectability of penguins in aerial surveys over the pack-ice off Antarctica

    Colin Southwell, Charles GM Paxton and David L. Borchers.

    Wildlife Research, Vol. 35, No. 4, 2008, pp. 349-357.

    Knowledge of penguin abundance at regional and circumpolar scales across the Southern Ocean is important for the development of ecosystem models and to estimate prey consumption by penguins to assess potential competition with fisheries' operations. One means of estimating penguin abundance is to undertake aerial surveys across the pack-ice surrounding Antarctica where penguins forage. However, it has long been recognised that aerial counts and resultant abundance estimates are likely to be negatively biased unless detectability is estimated and taken into account. Mark-recapture line-transect methods were used to estimate the detectability of penguin groups resting on ice floes during helicopter surveys over the pack- ice off Antarctica. Group size had the greatest effect of several measured covariates on detectability. Despite a concerted effort to meet the central assumption of conventional line-transect sampling (all objects on the transect line are detected), this was close to being achieved by single observers only in the case of the occasional very large group of >20 penguins. Emperor penguins were more detectable than Adelie penguins. Although observers undertook an extensive simulation training program before the survey, overall they improved in their ability to detect penguin groups throughout the survey. Mark-recapture line-transect methods can provide less biased estimation than conventional line-transect methods in aerial survey applications. This improvement comes with some costs, including the need for more demanding data-recording procedures and the need to use larger, more expensive aircraft. These additional costs will often be small compared with the basic cost, but the gain in terms of improved estimation may be substantial.

  20. Life-history patterns in marine birds

    V. S. Karpouzi and D. Pauly.

    Fisheries Centre research reports, Vol. 16, No. 10, 2008, pp. 27-53.

    The parameters of the von Bertalanffy growth equation for seabirds were estimated from previously published growth curves to allow within and between group comparisons of their life-history patterns. Overall, growth data were available for 447 seabird populations breeding around the globe, corresponding to 137 species, 13 families and four orders. A negative relationship between the logarithmic values of W! and K was identified for the orders of Charadriiformes, Pelecaniformes, Procellariiformes, and Sphenisciformes, as well as all seabird species combined. The values of the slope b ranged from -0.32 for the Sphenisciformes, to -0.12 for the Pelecaniformes, with a mean slope of -0.21, when all seabirds were considered

  21. PALAEOSPHENISCUS PATAGONICUS (AVES, SPHENISCIFORMES): NEW DISCOVERIES FROM THE EARLY MIOCENE OF ARGENTINA

    Carolina Acosta Hospitaleche, Liliana Castro, Claudia Tambussi and Roberto A. Scasso.

    Journal of Paleontology, Vol. 82, No. 3, May 2008, pp. 565-575.

    The penguin skeleton studied here constitutes the fourth partial skeleton found in Patagonia, and the third one with an associated humerus and tarsometatarsus. The finding of this partial skeleton identified with certainty as Palaeospheniscus patagonicus Moreno and Mercerat, 1891 (Aves, Sphenisciformes) allows the first description of elements other than the tarsometatarsus. The material comes from the basal sector of the Gaiman Formation (Early Miocene), located along the Atlantic coast of Chubut Province, south of Rawson city. This unit comprises a succession of shales, fine tuffs, sandstones, tuffaceous sandstones, and coquinas deposited in a shallow marine environment. These beds contain abundant marine vertebrates (sharks, dolphins, rays, birds), mollusk casts, and oyster beds. The skeleton includes: rostrum, two thoracic vertebrae, right coracoid without the distal end, left humerus, right femur, right tarsometatarsus, left fragmentary scapula, left coracoid, left radius without the distal end, proximal portion of left ulna, proximal end of left femur, and preacetabular part of the synsacrum. P. patagonicus would have been a medium-sized penguin weighing about 5 kg that inhabited the breeding colonies established in the nearby Bryn Gwyn area during the early Miocene. Despite the abundance of penguin remains known for Argentina, and the fact that they are among the birds with a better fossil record, this skeleton is an exceptional case. This finding allows a readjustment of the taxonomic criteria applicable to fossil and living species. [PUBLICATION ABSTRACT]

  22. Penguins as Marine Sentinels

    P. Dee Boersma.

    Bioscience, Vol. 58, No. 7, Jul/Aug 2008, pp. 597-607.

    From the tropics to Antarctica, penguins depend on predictable regions of high ocean productivity where their prey aggregate. Increases in precipitation and reductions in sea ice associated with climate warming are affecting penguins. The largest breeding colony of Patagonian (Magellanic) penguins, at Punta Tombo, Argentina, had approximately 200,000 breeding pairs in October 2006-a decline of 22% since 1987. In the 1980s and 1990s, petroleum pollution was a major source of Patagonian penguin mortality. In 1994, tanker lanes were moved 40 kilometers (km) farther off the coast of Chubut, and the dumping of ballast water and the oiling of penguins are now rare. However, penguins are swimming 60 km farther north from their nests during incubation than they did a decade ago, very likely reflecting shifts in prey in response to climate change and reductions in prey abundance caused by commercial fishing. These temperate penguin species, marine sentinels for southern oceans, demonstrate that new challenges are confronting their populations. [PUBLICATION ABSTRACT]

  23. Scaling laws of marine predator search behaviour

    David W. Sims, Emily J. Southall, Nicolas E. Humphries, et al.

    Nature, Vol. 451, No. 7182, Feb 28, 2008, pp. 1098-102.

    Many free-ranging predators have to make foraging decisions with little, if any, knowledge of present resource distribution and availability. The optimal search strategy they should use to maximize encounter rates with prey in heterogeneous natural environments remains a largely unresolved issue in ecology. Levy walks are specialized random walks giving rise to fractal movement trajectories that may represent an optimal solution for searching complex landscapes. However, the adaptive significance of this putative strategy in response to natural prey distributions remains untested. Here we analyze over a million movement displacements recorded from animal-attached electronic tags to show that diverse marine predators--sharks, bony fishes, sea turtles and penguins—exhibit Levy-walk-like behavior close to a theoretical optimum. Prey density distributions also display Levy-like fractal patterns, suggesting response movements by predators to prey distributions. Simulations show that predators have higher encounter rates when adopting Levy-type foraging in natural-like prey fields compared with purely random landscapes. This is consistent with the hypothesis that observed search patterns are adapted to observed statistical patterns of the landscape. This may explain why Levy-like behavior seems to be widespread among diverse organisms, from microbes to humans, as a 'rule' that evolved in response to patchy resource distributions. [PUBLICATION ABSTRACT]

  24. Severity of the Effects of Invasive Rats on Seabirds: A Global Review

    Holly P. Jones, Bernie R. Tershy, Erika S. Zavaleta, et al.

    Conservation biology the journal of the Society for Conservation Biology., Vol. 22, No. 1, February 2008, pp. 16-26.

    Invasive rats are some of the largest contributors to seabird extinction and endangerment worldwide. We conducted a meta-analysis of studies on seabird-rat interactions to examine which seabird phylogenetic, morphological, behavioral, and life history characteristics affect their susceptibility to invasive rats and to identify which rat species have had the largest impact on seabird mortality. We examined 94 manuscripts that demonstrated rat effects on seabirds. All studies combined resulted in 115 independent rat-seabird interactions on 61 islands or island chains with 75 species of seabirds in 10 families affected. Seabirds in the family Hydrobatidae and other small, burrow-nesting seabirds were most affected by invasive rats. Laridae and other large, ground-nesting seabirds were the least vulnerable to rats. Of the 3 species of invasive rats, Rattus rattus had the largest mean impact on seabirds followed by R. norvegicus and R. exulans; nevertheless, these differences were not statistically significant. Our findings should help managers and conservation practitioners prioritize selection of islands for rat eradication based on seabird life history traits, develop testable hypotheses for seabird response to rat eradication, provide justification for rat eradication campaigns, and identify suitable levels of response and prevention measures to rat invasion. Assessment of the effects of rats on seabirds can be improved by data derived from additional experimental studies, with emphasis on understudied seabird families such as Sulidae, Phalacrocoracidae, Spheniscidae, Fregatidae, Pelecanoididae, Phaethontidae, and Diomedeidae and evaluation of rat impacts in tropical regions.

  25. Transition to independence and evidence of extended parental care in the gentoo penguin (Pygoscelis papua)

    Michael J. Polito and Wayne Z. Trivelpiece.

    Marine Biology, Vol. 154, No. 2, Apr 2008, pp. 231-240.

    We used radio telemetry and observations to study the activity patterns and behavior of gentoo penguin chicks at Admiralty Bay, King George Island, South Shetland Islands in 2005 during their "fledging period"; defined as the time between a chick's first trip to sea and its final dispersal from the breeding colony. Gentoo penguins exhibited delayed dispersal of young and extended parental provisioning, behaviors not observed in other Pygoscelis species. Chicks took their first trip to sea at a mean age of 70 days of age, before finally departing the colony at a mean age of 82 days. During this fledging period, individual chicks made an average of five trips to sea. Trip duration increased significantly as chicks aged, with trips to sea becoming similar to literature values of adult foraging trips in both timing and duration. Behavioral observations and mass dynamics confirmed that many chicks were still being fed during this fledging period, with parental feeding behaviors most often observed in the late afternoon to evening hours. We hypothesize that these behaviors provide an opportunity for chicks to gain experience at sea prior to dispersal and might allow them to develop foraging skills before they are completely independent. [PUBLICATION ABSTRACT]

  26. Divergent responses of Pygoscelis penguins reveal a common environmental driver

    Jefferson T. Hinke, Kasia Salwicka, Susan G. Trivelpiece, George M. Watters and Wayne Z. Trivelpiece.

    Oecologia, Vol. 153, No. 4, Oct 2007, pp. 845-55.

    The responses of predators to environmental variability in the Antarctic Peninsula region have exhibited divergent patterns owing to variation in the geographic settings of colonies and predator life-history strategies. Five breeding colonies of Pygoscelis penguins from King George Island and Livingston Island, South Shetland Islands, Antarctica, were examined to (1) compare the responses of sympatric congeners to recent changes in their Antarctic ecosystem and (2) assess underlying causes for such responses. We used linear regression and correlation analyses to compare indices of abundance, recruitment, and summer breeding performance of the Adélie (P. adeliae), gentoo (P. papua), and chinstrap penguins (P. antarctica). Breeding colonies of Adélie and chinstrap penguins have declined by roughly 50% since the mid-1970s, and recruitment indices of Adélie penguins have declined by roughly 80%, but no such patterns are evident for gentoo penguins. Fledging success, however, has remained stable at all breeding colonies. The different trends in abundance and recruitment indices for each species, despite generally similar indices of summer performance, suggest that winter conditions contribute to the divergent responses among the penguins. In particular, strong correlations between indices of penguin and krill recruitment suggest that penguins in the South Shetland Islands may live under an increasingly krill-limited system that has disproportionate effects on the survival of juvenile birds.[PUBLICATION ABSTRACT]

  27. Effects of Giant Icebergs On Two Emperor Penguin Colonies in the Ross Sea, Antarctica

    Gerald L. Kooyman, David G. Ainley, Grant Ballard and Paul J. Ponganis.

    Antarctic Science, Vol. 19, No. 1, Mar 2007, pp. 31-38.

    The arrival in January 2001 in the south-west Ross Sea of two giant icebergs, C16 and B15A, subsequently had dramatic affects on two emperor penguin colonies. B15A collided with the north-west tongue of the Ross Ice Shelf at Cape Crozier, Ross Island, in the following months and destroyed the penguins' nesting habitat. The colony totally failed in 2001, and years after, with the icebergs still in place, exhibited reduced production that ranged from 0 to 40% of the 1201 chicks produced in 2000. At Beaufort Island, 70 km NW of Crozier, chick production declined to 6% of the 2000 count by 2004. Collisions with the Ross Ice Shelf at Cape Crozier caused incubating adults to be crushed, trapped in ravines, or to abandon the colony and, since 2001, to occupy poorer habitat. The icebergs separated Beaufort Island from the Ross Sea Polynya, formerly an easy route to feeding and wintering areas. This episode has provided a glimpse of events which have probably occurred infrequently since the West Antarctic Ice Sheet began to retreat 12 000 years ago. The results allow assessment of recovery rates for one colony decimated by both adult and chick mortality, and the other colony by adult abandonment and chick mortality.

  28. An improved model of heat transfer through penguin feathers and down

    N. Du, J. Fan, H. Wu, S. Chen and Y. Liu.

    Journal of theoretical biology, Vol. 248, No. 4, Oct 21, 2007, pp. 727-735.

    Penguins, mostly live in the extremely cold Antarctic, are known to have feathers and down, which are light weight, compact and extremely efficient in preventing heat loss. Nevertheless, the mechanisms of heat transfer through the penguin feathers and down, and how the unique characteristics of penguin feathers and down make them such good thermal insulators are not fully understood. In this paper, an integrated model of heat transfer through the penguin feathers and down is developed and computed using finite volume method, with the geometrical structure of the barbules being considered. Monte-Carlo method is adopted to determine the radiative absorption and emission constant in the integrated model. The effective thermal conductance of penguin feathers and down computed from our model compared well with the experimentally measured value reported in the literature. Three models (penguin model, random fibre model (fibre radius=3 mu m) and random fibre model (fibre radius=10 mu m)) are further simulated and compared. Results showed that the relative small radius of the barbules of penguin feather and their geometrical structure are responsible for the reduction of heat loss in cold environment.

  29. Same-sex sexual behavior in birds: expression is related to social mating system and state of development at hatching

    Geoff R. MacFarlane, Simon P. Blomberg, Gisela Kaplan and Lesley J. Rogers.

    Behavioral Ecology, Vol. 18, No. 1, Jan 2007, pp. 21.

    We report the findings of a phylogenetic comparative analysis examining patterns and frequency of occurrence of same-sex courtship and mounting behavior in birds. Our analysis has shown associations between same-sex sexual behavior and both mating system and degree of precociousness at hatching. The patterns of expression and frequency of occurrence of same-sex sexual behavior differed markedly for males and females. Patterns of same-sex sexual expression reflected the competitive sexes that actively solicit sexual interactions in heterosexual encounters. Male-male (MM) sexual behavior occurred across all mating systems, but MM mounting was significantly more prevalent in those species with facultative polygamy. The frequency of MM sexual behavior increased with degree of polygamy. Female-female (FF) sexual behavior (especially courtship) occurred most frequently in socially monogamous species and rarely occurred in species that display obligate polygamy (predominantly polygynous species). Both expression and frequency of FF sexual behavior was strongly related to the precocial state of development at hatching. FF sexual behavior is more likely to occur in species in which monogamy occurs together with the production of precocial offspring; that is, in monogamous species that are exceptions to the more common altricial mode of development. We suggest that requirement of biparental care in monogamous species may influence the greater expression of FF sexual behavior and longer term associations. Both spatial and behavioral dispersion of females and engagement in uniparental care may be important in explaining the lower incidence of FF sexual behavior in polygynous species. Social contexts where males congregate at communal leks or display areas may influence the greater expression and frequency of MM sexual behavior in polygynous species.

  30. The trophic link between squid and the emperor penguin Aptenodytes forsteri at Pointe Géologie, Antarctica

    Ilka Zimmer, Uwe Piatkowski and Thomas Brey.

    Marine Biology, Vol. 152, No. 5, Oct 2007, pp. 1187-1195.

    Cephalopod beaks retrieved from stomachs of dead emperor penguin chicks at Pointe Géologie, Terre Adélie, provide information on taxonomic and size composition of the penguin's squid diet, on the trophic range of the squid species preyed upon and on the fractional trophic impact of the penguin on the whole food web. Emperor penguins prey upon four squid species (Psychroteuthis glacialis, Kondakovia longimana, Gonatus antarcticus, Alluroteuthis antarcticus) and do not take squid larger than 480 mm mantle length. Larger squid live either below the penguin's diving range or are beyond its handling capacity. Nitrogen stable isotope ratios indicate that squids cover a range of about two trophic levels (2.5-8[per thousand] δ15N). The impact of the emperor penguin, however, concentrates on the upper part of this range, about 68% of its squid prey being >6[per thousand] δ15N. The principal components of the emperor's diet, fish, krill and squid, differ distinctly in average trophic level. Consequently the trophic position of the emperor penguin changes accordingly with diet composition and may differ by almost one trophic level between different emperor penguin colonies. [PUBLICATION ABSTRACT]

  31. Diving characteristics of southern rockhopper penguins (Eudyptes c. chrysocome) in the southwest Atlantic

    Klemens Pütz, Andrea Raya Rey, Nic Huin, Adrian Schiavini, Andrea Pütz and Bernhard H. Lüthi.

    Marine Biology, Vol. 149, No. 2, May 2006, pp. 125-137.

    The diving behaviour of southern rockhopper penguins (Eudyptes c. chrysocome) was studied at two breeding sites in the Southwest Atlantic: the Falkland Islands and Staten Island, Argentina. Incubating and brooding birds were equipped with time-depth recorders to monitor their foraging activities. Rockhopper penguins from Staten Island started their breeding season about 3 weeks earlier than their conspecifics from the Falkland Islands. The foraging area used by incubating males from the Falkland Islands comprised about 150,000 km2 to the northeast of the breeding site and was characterised by shelf and slope waters, whereas the foraging area of incubating males from Staten Island comprised 350,000 km2 of oceanic waters to the southeast of the breeding site. A number of dive parameters were measured and compared between the four study groups: Incubating males and brooding females from the Falkland Islands, and incubating males and females from Staten Island. In all study groups, dive depth correlated positively to light intensity, dive duration and vertical velocity. However, significant differences between various diving parameters of the study groups were noted, not only in terms of diving performance, but also as regards diving efficiency (DE). A principal component analysis (PCA) on 16 variables revealed that 75% of the variance could be explained by only two principal components: diving pattern (PC1) and diving effort (PC2). PC1 indicated that the birds from Staten Island, both males and females, dived deeper, covered a greater vertical distance per hour and had higher ascent rates, but spent less time underwater and at the bottom of a dive, and had a lower DE than conspecifics from the Falkland Islands. PC2, which included the percentage of foraging dives, the number of dives per hour, dive duration, bottom time and descent rate, differed significantly between incubating males from the Falkland Islands and the other three groups, which were all very similar. Overall, the diving behaviour was notably similar to that of conspecifics from the Indian and Pacific Oceans. The implications of the results in terms of intra-specific adaptations as well as potential threats from human activities are discussed.[PUBLICATION ABSTRACT]

  32. Foraging strategies and prey encounter rate of free-ranging Little Penguins

    Yan Ropert-Coudert, Akiko Kato, Rory P. Wilson and Belinda Cannell.

    Marine Biology, Vol. 149, No. 2, May 2006, pp. 139-148.

    There is little information on the effort put into foraging by seabirds, even though it is fundamental to many issues in behavioural ecology. Recent researchers have used changes in the underwater cruising speed of penguins to allude to prey ingestion since accelerations are thought to reflect the encounter and pursuit of prey. In this study, we attached minute accelerometers, to determine flipper beat frequency as a proxy for prey pursuit, to Little Penguins Eudyptula minor foraging in shallow waters in Western Australia. During diving, Little Penguins flapped continuously and at a regular pace of 3.16 Hz while descending the water column and throughout the bottom phase of most dives. However, the frequency and amplitude of wingbeats increased transitorily, reaching 3.5-5.5 Hz, during some dives indicating prey pursuit. Pursuit phases lasted a mean of 2.9 +/- 3.3 s and occurred principally during the bottom phases of dives (75.4%). Most dives in all birds (86%) had a clear square-shaped depth profile indicating feeding activity near the seabed in the shallow waters of the bays. Hourly maximum depth, time spent underwater, percentage of dives with pursuit events and catch per unit effort showed an overall increase from zero at ca. 0500 h to a maximum during the hours around mid-day before decreasing to zero by 1900 h. During pursuit phases, Little Penguins headed predominantly downward, probably using the seabed to assist them in trapping their prey. In the light of our results, we discuss depth use by Little Penguins and their allocation of foraging effort and prey capture success as a function of environmental conditions.[PUBLICATION ABSTRACT]

  33. Physiological Response to Feeding in Little Penguins

    JA Green, P. B. Frappell, T. D. Clark and P. J. Butler.

    Physiological and Biochemical Zoology, Vol. 79, No. 6, Dec 2006, pp. 1088-1097.

    Specific dynamic action (SDA), the increase in metabolic rate above resting levels that accompanies the processes of digestion and assimilation of food, can form a substantial part of the daily energy budget of free-ranging animals. We measured heart rate fH and rate of oxygen consumption VO2 in 12 little penguins while they digested a meal of sardines in order to determine whether they show specific dynamic action. In contrast to some studies of other penguin species, little penguins showed a substantial SDA, the magnitude of which was proportional to the size of the meal. The energy utilized in SDA was equivalent to 13.4% of the available energy content of the fish. Furthermore, animals such as penguins that forage in a cold environment will probably expend further energy in heating their food to body temperature to facilitate efficient digestion. It is estimated that this additional energy expenditure was equivalent to 1.6%-2.3% of the available energy content of the fish, depending on the time of year and therefore the temperature of the water. Changes in fH during digestion were qualitatively similar to those in VO2, implying that there were no substantial circulatory adjustments during digestion and that the relationship between fH and VO2 in penguins is unaffected by digestive state.

  34. A Stable Isotopic Investigation into the Causes of Decline in a Sub-Antarctic Predator, the Rockhopper Penguin Eudyptes chrysocome

    Geoff M. Hilton, David R. Thompson, Paul M. Sagar, Richard J. Cuthbert, Yves Cherel and Sarah J. Bury.

    Global Change Biology, Vol. 12, No. 4, Apr 2006, pp. 611.

    The causes of decline of a sub-Antarctic predator, the rockhopper penguin (Eudyptes chrysocome), were investigated. The objective was to examine whether rockhopper penguin population decline was associated with a shift towards lower primary productivity in the ecosystem in which they feed, or a shift to a diet of lower trophic status and lower quality. Stable isotope analyses of carbon and nitrogen were employed in time series of rockhopper penguin feather samples, in order to reconstruct the species' ecological history. Having controlled temporally for the Suess Effect and for increases in carbon dioxide concentration in seawater, it was found that overall delta super(15)C signatures decreased significantly over time in rockhopper penguins from seven breeding sites. There was strong evidence that delta super(15)N signatures were negatively related to sea surface temperatures across sites.

  35. COOL BIRDS

    Susan Milius.

    Science News, Vol. 168, No. 17, Oct 22, 2005, pp. 266-267,269.

    Milius takes a look at how emperor penguins survive through the harsh winters of Antarctica. Emperor penguins fish for a living, and right before the breeding season, they binge fish to prepare them for many months of extreme dieting.

  36. Sex-specific foraging ecology of Adelie Penguins within pairs

    C. Gilbert, G. Kuntz, J-M Canonville, M. Beaulieu and A. Ancel.

    Alauda, Vol. 73, No. 3, 2005, pp. 293-294.

    Adelie Penguin (Pygoscelis adeliae) biology is pretty well documented but at the scale of a pair, many questions are still to be solved. Because each member of a breeding pair is alternately foraging at sea or breeding on land, a question arises: which member of a pair invests more in reproduction? To elucidate this question, we equipped, under general anaesthesia, both members of 5 pairs with data loggers recording body and ambient temperatures along with hydrostatic pressure and light intensity. We observed that the males hunting effort was higher than for their respective partners: 44% of dives performed by males exceeded their theoretical aerobic dive limit (110 s) vs. 22% in females. Dives were also deeper in males than in females. Both males and females reduced their foraging effort by decreasing their deep body temperature likely to save energy and to hunt longer at sea. During a trip at sea, foraging effort increased toward the end of each dive bout. Despite our small sample size we can conclude that the males invest more in reproduction than their mates.

  37. Shore Leave

    Erin Espelie.

    Natural History, Vol. 114, No. 10, Dec 2005/Jan 2006, pp. 7-8.

    Espelie presents a photograph depicting a trio of king penguins—perhaps unattached, perhaps on break—ambling by, while several southern elephant seals caught R & R. A male southern elephant seal, like the juvenile in the fore-ground, is unmistakable, with an inflatable nose and four tons of flesh—this juvenile is about seven years old, spends his summers on land, molting and resting. He would have competed with other, stronger males for a mate five months earlier, going without food for many weeks.

  38. THE INFLUENCE OF LAYING DATE AND MATERNAL AGE ON EGGSHELL THICKNESS AND PORE DENSITY IN YELLOW-EYED PENGUINS

    Melanie Massaro and Lloyd S. Davis.

    The Condor, Vol. 106, No. 3, Aug 2004, pp. 496-505.

    In many bird species, eggs laid late in the breeding season hatch after a shorter incubation period than eggs that were laid early. The proximate mechanisms that cause these seasonal declines in incubation length remain poorly understood. We tested in Yellow-eyed Penguins (Megadyptes antipodes), Hipfner's hypothesis that late-laid eggs have thinner eggshells with a higher pore density that allow embryos to develop more rapidly than in early-laid eggs. In this species incubation length declines with increasing female age, so we also investigated whether eggshell thickness and pore density varies with female age. In addition, differences in shell thickness and pore density between first- and second-laid eggs of the same clutch were examined. Eggshell thickness did not change with laying date and was not related to length of incubation. In contrast, pore density increased with laying date and was negatively related to incubation length in first-laid eggs. Eggshell thickness and pore density increased with female age. Second-laid eggs had a lower pore density and approximately 900 fewer pores than first-laid eggs of the same clutch. Our study suggests that embryos of late-laid eggs may be able to develop faster than embryos of early-laid eggs because of a greater capacity for gas exchange. Further work on eggshell porosity could provide answers to some long-standing questions about the evolutionary advantages of seasonal declines in incubation periods and their underlying mechanisms. [PUBLICATION ABSTRACT] Key words: eggshell thickness, female age, incubation period, laying date, Megadyptes antipodes, pore density, Yellow-eyed Penguin.

  39. Penguin-mounted cameras glimpse underwater group behaviour

    A. Takahashi, K. Sato, Y. Naito, MJ Dunn, P. N. Trathan and J. P. Croxall.

    Proceedings of the Royal Society of London, Series B: Biological Sciences, Vol. 271, Aug 7, 2004, pp. 281-282.

    Marine birds and mammals spend most of their lives in the open ocean far from human observation, which makes obtaining information about their foraging behavior difficult. Here, we show, by use of a miniaturized digital camera system, the first direct evidence (to our knowledge) of underwater group behavior in free-ranging penguins. Penguins swim closely accompanied by other bird(s) during 24% of their possible foraging dives. This finding confirms that such miniaturized camera technology has broad applicability for advancing our knowledge about the previously unknown social interactions of marine animals at depth.

  40. Phylogeny Of Extant Penguins Based On Integumentary And Breeding Characters

    N. P. Giannini and S. Bertilli.

    Auk, Vol. 121, No. 2, Apr 2004, pp. 422-434.

    A phylogeny of extant penguins (18 forms) was estimated on the basis of 70 integumentary and breeding characters. Integumentary characters included structure and color of bill and legs, and plumage of adult, immature, and downy chick. Breeding characters included eggs, nesting, and sociability of immatures. Gavia was placed at the root, and 11 species of representative procellariiform groups completed the outgroup. A heuristic parsimony analysis under implied character weights was performed. Ingroup resolution was complete. The analysis recovered monophyly of Sphenisciformes and all the traditional genera. The ingroup topology was ((Eudyptula + Spheniscus) (Aptenodytes (Pygoscelis (Megadyptes + Eudyptes)))). Two suprageneric groups, (Eudyptula + Spheniscus) and (Megadyptes + Eudyptes), were well supported. Additional analyses under equal weights resulted in a consensus topology that differed only in the internal resolution of Spheniscus. Integumentary and breeding characters performed optimally at the ordinal and generic levels, and also provided resolution and varying degrees of support at the supra- and intrageneric levels.

  41. WHY PENGUIN EGGSHELLS ARE THICK

    P. Dee Boersma, Ginger A. Rebstock and David L. Stokes.

    The Auk, Vol. 121, No. 1, Jan 2004, pp. 148-155.

    Like most other penguin species, Magellanic Penguins (Spheniscus magellanicus) are large-bodied birds that incubate their eggs for a prolonged period on hard substrates with little nesting material - all circumstances that could lead to high rates of egg breakage. However, Magellanic Penguin eggs at Punta Tombo, Argentina are seldom broken. From 1984 to 2001, only 2.6% of 10,023 eggs in our study areas broke or cracked. Most of those were broken in unusual or catastrophic events, mainly penguin fights and rainstorms. Low breakage rates appear to be attributable to thick eggshells. Shells of Magellanic Penguin eggs averaged 0.81 mm without the egg membranes – at least 56% thicker than expected for bird eggs of similar mass. The calcium required for those thick eggshells cannot be supplied by normal food intake because females lay eggs during a fasting period. It is also unlikely that sufficient skeletal calcium can be mobilized. An alternative potential calcium source is mollusk shells. To determine whether female penguins were selectively ingesting calcium to form thick eggshells, we examined stomach contents of birds during the egg period (settlement, egg laying, and early incubation) and the post-egg period (late incubation and chick rearing). Both females and males were more likely to have mollusk shells in their stomachs during the egg period than during the post-egg period. However, females were much more likely than males to have shells in their stomachs during the egg period, whereas the proportions of males and females with mollusk shells did not differ in the post-egg period. Selective ingestion of mollusk shells by Magellanic Penguins, resulting in thick eggshells, appears to be an adaptive response that reduces egg breakage. Received 16 January 2003, accepted 5 October 2003. [PUBLICATION ABSTRACT]

  42. Diving behavior of Magellanic penguins (Spheniscus magellanicus) at Punta Tombo, Argentina

    Brian G. Walker and P. Dee Boersma.

    Canadian journal of zoology, Vol. 81, No. 9, Sep 2003, pp. 1471-1483.

    Geographic and temporal variability in the marine environment affects seabirds' ability to find food. Similarly, an individual's body size or condition may influence their ability to capture prey. We examined the diving behavior of Magellanic penguins (Spheniscus magellanicus) at Punta Tombo, Argentina, as an indicator of variation in foraging ability. We studied how body size affected diving capability and how diving varies among years and within breeding seasons. We also compared diving patterns of Magellanic penguins at Punta Tombo with those of birds in two colonies at the opposite end of the species' breeding range. Larger penguins tended to dive deeper and for longer than smaller birds. Trips were longer during incubation and in the years and colonies with lower reproductive success, which suggests that in those instances birds were working hard to recover body condition and feed chicks. Average dive depths, average dive durations, and percentages of time spent diving were always similar. We found that the only parameter these penguins consistently modified while foraging was the length of their foraging trip, which suggests that penguins at Punta Tombo were diving at maximum rates to find their preferred prey. Increasing trip length, we suggest, is a physiologically conservative solution for increasing the likelihood of encountering prey. [PUBLICATION ABSTRACT]

  43. In-depth studies of Magellanic penguin (Spheniscus magellanicus) foraging: can we estimate prey consumption by perturbations in the dive profile?

    A. SimeoneR P. Wilson.

    Marine Biology, Vol. 143, No. 4, Oct 2003, pp. 825-831.

    A new concept based on analysis of dive depth data was developed to help estimate prey consumption in ten free-ranging Magellanic penguins (Spheniscus magellanicus) that were brooding chicks. By simultaneously analysing the undulations in the dive depth profile (measured by time-depth recorders, TDRs) and beak opening (obtained from the recently developed intra-mandibular angle sensors, IMASEN), it was possible to determine the proportions of the undulations in the dive profile that resulted (or not) in prey capture. This methodology allowed the number of prey consumed to be estimated with a mean error of 10±6% using TDR data alone. If the mean mass of prey is known, then the overall mass of prey consumed per unit time can be determined. Additionally, the method allows estimation of the depth at which prey is taken and thus indicates how penguins exploit the water column. Due to its simplicity, the proposed methodology has applications for other Spheniscus penguin species and should be considered for other marine endotherm divers that show undulations in the dive depth profile.

  44. Cephalopods in the trophic relations off southern Brazil

    RA dos Santos and M. Haimovici.

    Bulletin of Marine Science, Vol. 71, No. 2, Sep 2002, pp. 753-770.

    Trophic relations of cephalopods in southern Brazil were investigated from predation on cephalopods by 71 species of potential predators, including two squids, 47 fishes, seven seabirds and 15 marine mammals from shelf, upper slope and oceanic adjacent waters. In all, 27 families and 41 species of cephalopods were identified from stomach contents. The number of families ranged from six, in the diet of shelf predators, to 27 families in those from upper slope and adjacent oceanic waters. The most frequent cephalopod prey on the shelf was Loligo sanpaulensis, particularly important in the diet of Franciscana dolphin Pontoporia blainvillei, occurring also in the diet of the penguin Spheniscus magellanicus, the fur seals Arctocephalus australis, A. gazella, A. tropicalis, and several benthic and demersal fishes. Ommastrephidae, mainly Illex argentinus and Ornithoteuthis antillarum, was the most frequent family in the diet of predators from upper slope and adjacent oceanic waters. Illex argentinus was an important prey for the wreckfish Polyprion americanus, the bigeye tuna Thunnus obesus, the swordfish Xiphias gladius and some marine mammals, especially in their winter and spring northward reproductive migration. Ornithoteuthis antillarum was frequent in the diet of the skipjack tuna Katsuwonus pelamis, the albacore Thunnus alalunga, the yellowfin tuna T. albacares, the Atlantic sailfish Istiophorus albicans and the white marlin Tetrapturus albidus. Ammoniacal squids, such as Ancistrocheirus lesueurii, Histioteuthis spp, Chiroteuthis veranii and Octopoteuthis sp, were mainly found in stomach contents of the blue shark, Prionace glauca, the pygmy sperm whale Kogia breviceps, the dwarf sperm whale K. sima, the long-finned pilot whale, Globicephala melas and oceanic seabirds. The relative importance, based on frequency of occurrence, of cephalopods as food resources seems to be higher in the food chains of the upper slope and adjacent oceanic waters, when compared to the continental shelf.

  45. Love, penguin style

    Angie Pelekidis.

    Wildlife Conservation, Vol. 105, No. 3, May/Jun 2002, pp. 72.

    A number of monogamous relationships between penguins at the New York Aquarium are examined. The sex ratio in the colony is 22 males to ten females.

  46. Short Underwater Opening Of The Beak Following Immersion In Seven Penguin Species

    Y. Ropert-Coudert, A. Kato, R. P. Wilson and M. Kurita.

    Condor, Vol. 104, No. 2, May 2002, pp. 444-448.

    Videocamera recordings of seven species of penguin, Emperor (Aptenodytes forsteri), Humboldt (Spheniscus humboldti), Adelie (Pygoscelis adeliae), Chinstrap (P. antarctica), Gentoo (P. papua), Macaroni (Eudyptes chrysolophus) and Rockhopper (E. chrysocome), swimming in large aquaria revealed that birds opened their beak underwater for less than a second immediately after initiating a dive. Overall, this beak-opening occurred in 64% of the immersions but, in all species, was associated with quick transitions between air and water, such as in porpoising or dives that were initiated rapidly. Two hypotheses are proposed to explain this behavior: beak-opening may be a signal that initiates bradycardia, such as is observed in unrestrained diving animals, or beak-opening may be associated with chemoreception to help detect potential prey or predators. Breve Apertura del Pico en Pingueinos luego de SumergirseOriginal Abstract: En acuarios registramos con camara de video a siete especies de pingueinos, Aptenodytes forsteri, Spheniscus humboldti, Pygoscelis adeliae, P. antarctica, P. papua, Eudyptes chrysolophus y E. chrysocome. Los registros indicaron que las aves abren el pico bajo el agua por menos de un segundo inmediatamente despues de sumergirse al iniciar el buceo. En total, esta apertura del pico se registro en el 64% de las inmersiones y en todas las especies ocurrio preferentemente en situaciones de transicion rapida entre aire y agua, como en 'porpoisinga o en buceos que se iniciaron abruptamente. Se proponen dos hipotesis para explicar esta conducta: la apertura del pico puede servir como una senal para iniciar la bradicardia, como se observa en animales buceando voluntariamente, o bien la apertura del pico podria estar asociada a quimiorecepcion para detectar potenciales presas o depredadores.

  47. (Delta)(15)N and (Delta)(13)C measurements of Antarctic peninsula fauna: Trophic relationships and assimilation of benthic seaweeds

    Kenneth H. Dunton.

    American Zoologist, Vol. 41, No. 1, Feb 2001, pp. 99-112.

    Measurements of delta(13)C, delta(15)N, and C/N for a variety of Antarctic peninsula fauna and flora were used to quantify the importance of benthic brown algae to resident organisms and determine food web relationships among this diverse littoral fauna. Delta(13)C values ranged from -16.8% for benthic algal herbivores (limpets) to -29.8% for the krill, Euphausia superba; the average pooled value for brown macroalgae, including their attached filamentous diatomas, was -20.6%.

  48. Energetics of Free-Ranging Seabirds

    H. I. Ellis and G. W. Gabrielsen.

    Boca Raton, FL: CRC Press LLC, 2001.

    Nearly 30 years ago, Calder and King (1974), noting that metabolic rates on 38 species of passerine and 34 species of nonpasserine birds had been measured since 1950 and recognizing the predictive power of allometric equations, asked whether it was better to add more birds to the list or to ask new questions. Of course, both happened. In fact, adding more species to the list in part led to new questions. Among these developments has been the ability to look at groups of birds in terms of both their phylogeny and their ecology. One such approach has been to single out seabirds as an ecological group (Ellis 1984, Nagy 1987). In the more than 15 years since a comprehensive review of seabird energetics has appeared (Ellis 1984), the information on basal metabolic rates (BMR) in this group has doubled and the reports on field metabolic rates (FMR, using doubly labeled water) have more than tripled. New analyses using both of these measurements have appeared during that time. It is the goal of this chapter to summarize our current knowledge of seabird energetics, provide a comprehensive review of BMR and FMR measurements, and examine many correlates of both. The relationships of BMR with color and activity pattern (Ellis 1984) need no further development. However, unlike the earlier review, we treat thermoregulation and provide information on thermal conductance and lower critical limits of thermoneutrality. For a comprehensive treatment of avian thermoregulation, refer to Dawson and Whittow (2000). Lustick (1984) remains the best source on seabird thermoregulation generally. Ellis (1984) demonstrated a latitudinal gradient for BMR in Charadriiformes. We reevaluate that gradient and consider whether such an analysis can be extended outside that order. We examine a variety of metabolic costs, including locomotion, and survey information on community energetics, critiquing old models and suggesting new ones. In this chapter, we limit ourselves mainly to adults in the four orders of seabirds: Sphenisciformes, Procellariiformes, Pelecaniformes, and Charadriiformes. Where feasible, we also include available information on sea ducks (Anseriformes). References to shorebirds or other birds are made only when necessary. But because the energetics of seabird migration is so poorly known, we direct the reader to those publications, relevant for shorebirds, which may provide useful insights (e.g., Alerstam and Hedenstroem 1998).

  49. Fishing disturbance and marine biodiversity: the role of habitat structure in simple soft-sediment systems

    S. F. Thrush, JE Hewitt, G. A. Funnell, et al.

    Marine Ecology Progress Series, Vol. 223, Nov 2001, pp. 261-276.

    Broad-scale anthropogenic disturbances that reduce the density of epifauna and homogenise surficial sediments can have important consequences for seafloor biodiversity. We investigated the habitat structure and macrofaunal diversity of relatively simple soft-sediment habitats over a number of spatial scales (cm to km) to identify the role of habitat structure in influencing macrobenthic diversity and to assess the validity of using habitat structure as a surrogate measure for biodiversity. We sampled 10 locations with differences in habitat structure using a sampling design that nested macrobenthic core samples within videoed transects of the seafloor. This allowed us to determine relationships between observable habitat structure and macrobenthic diversity at a number of spatial scales. We characterised elements of habitat structure based on direct counts of surficial sediment characteristics and the presence of other immobile features, many of which were biogenic in origin. We also used multivariate measures (the relative multivariate dispersion, the mean and range of the Bray-Curtis dissimilarity along the transects) to characterise habitat structure at the transect scale. We developed regression models based on measures of habitat structure that explained 74 to 86% of the variance in macrobenthic diversity. This result suggests that removal of habitat structure in relatively low-structure soft-sediment systems will significantly decrease their biodiversity, and consequently that of the wider marine ecosystem.

  50. Health evaluation of penguins (Sphenisciformes) following mortality in the Falklands (South Atlantic)

    I. F. Keymer, H. M. Malcolm, A. Hunt and D. T. Horsley.

    Diseases of aquatic organisms, Vol. 45, No. 3, Aug 2, 2001, pp. 159-169.

    In the Falklands, heavy mortality of rock-hopper penguins Eudyptes chrysocome occurred during the 1985-86 breeding season. Starvation was diagnosed as the primary cause of death, possibly caused by a shortage of euphausiid crustaceans (krill) due to unusual meterological conditions. `Puffinosis' may possibly have been a contributory factor; otherwise no conclusive evidence of infectious disease or toxicosis was found and also no evidence of radioactive contamination. In the 1986-87 breeding season no unusual mortality occurred, but 99 apparently healthy penguins were examined, i.e., rockhoppers Eudyptes chrysocome syn E. crestatus, gentoos Pygoscelis papua and Magellanics Spheniscus magellanicus. Full necropsies were carried out on 54. Tissue examinations were made for cadmium, copper, iron, manganese, mercury, lead and zinc. High tissue cadmium concentrations found in healthy birds in 1987 were similar to those in penguins which died in 1986, and therefore not considered to be of pathological significance. Although there has been no repetition of the unusually hot 1985-86 breeding season in the Falklands, penguins and other seabirds have had fluctuating breeding successes since then. The precise cause, including the roles of meteorological conditions and overexploitation of some forms of prey species, is unclear.

  51. Long-term fasting and re-feeding in penguins

    R. Groscolas and J-P Robin.

    Comparative Biochemistry and Physiology, A, Vol. 128, No. 3, Mar 2001, pp. 643-653.

    Spontaneous fasting during reproduction (sometimes with a full stomach) and moult is a major characteristic of the annual cycle of penguins. Long-term fasting (up to four months in male emperor penguins) is anticipated by the accumulation of fat (incubation fast) and of fat and protein (moult fast). During most of the incubation fast, birds rely almost entirely on lipids as an energy source, body proteins being spared. However, below a critical (but non-total) fat store depletion, marked behavioural, metabolic, and endocrine changes occur. Spontaneous locomotor activity increases and the egg is transitorily left unincubated for increasingly long periods, until its definitive abandon and the bird departs to re-feed at sea. These changes are thought to be activated by an endogenous refeeding signal triggered before lethal energy depletion. An increase in body protein catabolism in the face of a reduction in lipid availability and utilisation, and an increase in circulating corticosterone vs. a decrease in plasma prolactin, are likely to be major metabolic and hormonal components of this signal. The survival and rapid restoration of energy stores in birds having departed to re-feed at a stage of near total lipid depletion demonstrates the effectiveness of the re-feeding signal. Penguins, and possibly other seabirds, are therefore appropriate animal models for understanding the long-term interactions between body energy reserves and fasting, breeding and feeding physiology and behaviour.

  52. "A review of the foraging zones of satellite-tracked seabirds in the Southern Ocean"

    Y. Cherel, CA Bost and H. Weimerskirch.

    Paris: Institut Oceanographique, 2001, 57-82

    The article reviews data collected on the feeding ecology of seabirds from the Southern Ocean using satellite telemetry. Seabirds include penguins, albatrosses and the largest species of petrels. Depending on the species, main foraging areas are first, waters over the continental shelf and slope, and second, various zones of the oceanic domain, including the subtropical zone, the polar front and the polar frontal zone (and eddies within it), and Antarctic waters. Temporal changes in the foraging areas and distances were found, as differences between males and females and between closely-related species. Some procellariid species use a two-fold strategy during the chick-rearing period, using in alternance foraging areas close by and far away their breeding localities. Instrumented seabirds have the potential to collect useful information on physical parameters and on the marine resources of the pelagic ecosystem, thus complementing classical oceanographic studies. Finally, satellite tracking clearly indicates the marine areas that need to be protected for the conservation of austral seabirds.Original Abstract: Cet article synthetise les donnees obtenues sur la biologie des oiseaux de mer de laocean Austral grace a lautilisation de balises satellitaires. Il concerne principalement les manchots, les albatros et les plus grandes especes de petrels. Le suivi satellitaire a permis une categorisation des zones preferentielles daalimentation, en fonction de leurs caracteristiques oceanographiques : les eaux neritiques, le talus peri-insulaire et le vaste domaine oceanique (zone subtropicale, front polaire et zone polaire frontale et, au milieu de celle-ci, les structures tourbillonnaires, et enfin la zone antarctique). Les lieux daalimentation varient en fonction du cycle reproducteur et/ou de la saison. Les adultes de certaines especes utilisent pendant la periode daelevage du poussin une strategie double avec des zones daalimentation soit proches, soit tres eloignees des colonies. Des differences males-femelles et entre especes proches ont egalement ete notees. Enfin, les oiseaux suivis par telemetrie sont maintenant utilises comme auxiliaires oceanographiques pour recueillir des informations sur les parametres physiques et les ressources marines de laecosysteme pelagique. La localisation satellitaire indique egalement quelles sont les zones marines a proteger en priorite pour la conservation des oiseaux marins de laocean Austral.

  53. "Seabird Systematics and Distribution: A Review of Current Knowledge"

    M. de L.Brooke.

    Boca Raton, FL: CRC Press LLC, 2001.

    This review of systematics and distribution will be restricted to the groups of birds traditionally considered as seabirds. These groups are the Sphenisciformes. Procellariiformes, Pelecaniformes, and certain families among the Charadriiformes (Table 3.1). And I begin by explaining the significance of the restriction. While all species among the Sphenisciformes (penguins) and Procellariiformes (albatrosses, petrels, shearwaters, fulmars, and allies) are seabirds, this is not universally true for members of the other two orders. Among the Pelecaniformes, tropicbirds, frigatebirds, and boobies are exclusively seabirds. On the other hand, the various species of cormorant, anhinga (= darter), and pelican can be strict seabirds, or freshwater birds, or are able to thrive in both environments. But at least all members of the order are waterbirds. That is not true of the Charadriiformes, an order which comprises some 200 species of shorebirds plus five groups considered to be primarily seabirds, namely, the gulls, terns, skuas, skimmers, and auks. Of these, the auks and skuas are strict seabirds while different species of gull, tern, and skimmer are variously associated with the sea, or with freshwater, or with estuaries. It is evident already that the distinction between seabirds and other birds is not wholly clearcut. There are, for example, species of duck, grebe, and loon that may spend a substantial fraction of the year floating on salt water — yet these species are not considered to be seabirds. On the other hand, some species traditionally considered to be seabirds spend much of their lives far from the sea. The Brown-headed Gull (Larus brunnicephalus), breeding on the Tibetan Plateau, springs to mind.

  54. "Sphenisciformes"

    L. S. Davis.

    London: Academic Press, Harcourt Science & Technology, 2001.

    Penguins, with their upright stance and dinner-jacket plumage, constitute a distinct and unmistakable order of birds (Sphenisciformes). Granted there are a few embellishments here and there – the odd crest, a black line or two on the chest - but otherwise, penguins conform to a very conservative body plan. The design of penguins is largely constrained by their commitment to an aquatic lifestyle. Penguins have essentially returned to the sea from which their ancestors, and those of all tetrapods, came. In that sense, they share more in common with seals and sea turtles than they do with other birds. Their spindle-shaped bodies and virtually everything about them have evolved in response to the demands of living in water.

  55. A 3,000-year record of penguin populations

    Liguang Sun, Zhouqing Xie and Junlin Zhao.

    Nature, Vol. 407, No. 6806, Oct 19, 2000, pp. 858.

    There are no historical records of changing penguin populations in the maritime Antarctic. Here we analyze the concentration of "bio-elements" in a lake-sediment core dating back approximately 3,000 radiocarbon years. We found that the deposition of penguin droppings had a significant effect on the geochemical composition of the sediment core. Changes in sediment geochemistry reflect fluctuations in penguin numbers and suggest that variations in climate had an impact on penguin populations, which peaked somewhere between 1,400 and 1,800 years ago. We collected sediment cores from a lake on the Ardley Peninsula (maritime Antarctica) during the fifteenth China Antarctic Research Expedition (December 1998--March 1999) using a 12-cm-diameter PVC pipe.

  56. Explanatory history of the origin of feathers

    Walter J. Bock.

    American Zoologist, Vol. 40, No. 4, Sep 2000, pp. 478-485.

    Historical-narrative evolutionary explanations for the origin and further evolution of avian feathers involve two steps. The best explanation for the evolutionary origin of feathers would be one consistent with historical-narrative evolutionary explanations for the origin and further evolution of other features in the history of birds.

  57. Morphological aspects of the heart of the northern rockhopper penguin (Eudyptes chrysocome moseleyi): possible implication in diving behavior and ecology?

    Charles M. Drabek and Yann Tremblay.

    Polar Biology, Vol. 23, No. 12, Nov 2000, pp. 812-816.

    We compared the heart morphology of the small, deep-diving northern rockhopper penguin to the hearts of small, shallow-diving and large, deep-diving penguin species. The rockhopper penguin had a heart larger than expected for its body mass, and its heart weight/body weight was significantly greater than in the larger Adelie penguin. We found the rockhopper's right ventricle weight/heart weight to be significantly greater than this relationship in both the larger chinstrap and Adelie penguins. The relationship of the right to left ventricular weights in the rockhopper heart is not different to that of the large, deepest-diving emperor penguin. A larger heart in the rockhopper penguin might be related to its diving behavior and ecology if it contributes to diving efficiency during foraging by increasing lung perfusion during surface recovery. This would lead to decreased surface time.

  58. Seabirds as monitors of upper-ocean thermal structure. King penguins at the Antarctic polar front, east of Kerguelen sector

    M. Koudil, J. B. Charrassin, Y. Le Maho and CA Bost.

    Comptes Rendus de l'Academie des Sciences, Serie III.Sciences de la Vie/Life Sciences, Vol. 323, No. 4, 2000, pp. 377-384.

    The main objective of this work was to assess the potential of diving birds to monitor the hydrographic features near the Antarctic polar front. We compared the temperature/depth profiles recorded by instrumented King penguins Aptenodytes patagonicus at Kerguelen Islands (South Indian Ocean) with the oceanographic and remote sensing (satellite) data available for the same area during the same season. The birds were equipped with time/depth/temperature recorders or Argos transmitters. In addition, two birds were instrumented (of which one successfully) both with a time/depth /temperature recorder and an Argos transmitter. King penguins foraged as far as 400 km from the coast, in water masses with a vertical temperature structure characteristic of the region just south of the polar front. The temperature/depth profiles recorded throughout the dives (up to 270 m) revealed a pronounced thermocline. A three-dimensional distribution of water temperature was reconstructed. Comparison with previous hydrographic data shows a high correlation. Instrumented predators may therefore usefully and cheaply complement the database provided by conventional hydrographic surveys and remote sensing, especially in distant and rough areas such as the Southern Ocean.Original Abstract: Utilisation des oiseaux marins pour le suivi des temperatures marines. Le manchot royal dans la zone du front polaire Antarctique. Des manchots royaux Aptenodytes patagonicus instrumentes ont permis en mars 1995 d'etudier en detail les profils thermiques de la couche d'eau de sub-surface tout au long de leur deplacements dans le secteur oceanique Est des iles Kerguelen (partie centrale sud de l'ocean Indien). Les oiseaux etaient equipes de balises Argos afin de suivre leurs deplacements en haute mer (jusqu'a 400 km des cotes) ou de systemes electroniques miniaturises echantillonnant en continu la temperature de l'eau selon la profondeur des plongees (0-270 m). Les profils de temperature selon la profondeur ont permis de reconstituer une thermocline tres prononcee, caracteristique de la zone du front polaire, discontinuite oceanique majeure longeant l'est de Kerguelen. La representation en trois dimensions de la structure thermique de la region du front polaire est en accord avec les resultats des precedentes campagnes hydrographiques. En conclusion, les bases de donnees provenant de predateurs marins instrumentes peuvent completer efficacement, et pour un cout financier modique, les donnees issues des campagnes oceanographiques, notamment dans des regions difficiles d'acces comme l'ocean Austral.

  59. Sexual dimorphism and sexual selection in foraging strategies of northern Giant Petrels Macronectes halli during the incubation period

    J. Gonzalez-Solis, J. P. Croxall and A. G. Wood.

    Marine Ornithology, Vol. 28, No. 2, Mar 2000.

    Giant petrels Macronectes spp. are the most sexually dimorphic of all seabirds. We used satellite-tracking and mass change during incubation to investigate the influence of sexual size dimorphism, in terms of the inter-sexual food competition hypothesis, on foraging and fasting strategies of Northern Giant Petrels at South Georgia. Females foraged at sea, whereas males foraged mainly on the South Georgia coast, scavenging on seal and penguin carcasses. Foraging effort (flight speed, distance covered, duration of foraging trips) was significantly greater for males than for females. Females could not compensate for the mass loss during the incubation fast while foraging, suggesting greater incubation costs for females than for males. Both sexes regulated the duration and food intake of foraging trips, depending on the depletion of body reserves. The importance of fasting endurance, competition over food and flight metabolic rates are likely to differ between sexes owing to differences in foraging strategies, thus maintaining sexual size dimorphism. We suggest that sexual segregation of foraging strategies arose from size-related dominance at carcasses, promoting sexual size dimorphism.

  60. Summer at-sea distribution of seabirds and marine mammals in polar ecosystems: A comparison between the European Arctic seas and the Weddell Sea, Antarctica

    C. R. Joiris.

    Journal of Marine Systems, Vol. 27, No. 1-3, Dec 2000, pp. 267-276.

    The summer at-sea distribution of seabirds and marine mammals was quantitatively established both in Antarctica (Weddell Sea) and in the European Arctic: Greenland, Norwegian and Barents seas. Data can directly be compared, since the same transect counts were applied by the same team from the same icebreaking ship in both regions. The main conclusion is that densities of seabirds and marine mammals are similar in open water and at the ice edge from both polar regions, while the presence of Adelie penguins, minke whales and crabeater seals in densities more than one order of magnitude higher in Antarctic pack-ice must reflect a major ecological difference between both polar systems. The ecological implications of these observations are discussed, especially concerning important primary and secondary (krill) productions under the Weddell Sea pack-ice.

  61. Validation of oesophagus temperature recording for detection of prey ingestion on captive Adelie penguins (Pygoscelis adeliae)

    Y. Ropert-Coudert, J. Baudat, M. Kurita, et al.

    Mar.Biol., Vol. 137, No. 5-6, Mar 2000, pp. 1105-1110.

    The efficiency of oesophagus and stomach temperature loggers to detect ingestion of prey items was studied in captive Adelie penguins (Pygoscelis adeliae) fed on land in Antarctica and in an aquarium in Japan. On land, the detection rate was studied for different masses of prey delivered at various frequencies, while in the pool the delay between capture and swallowing was investigated. The rate at which food items were detected and the magnitude of the temperature drops induced were higher in the oesophagus than in the stomach. Where small food items were delivered at a high frequency, birds collected prey items in the beak before swallowing them. Thus, oesophagus sensors may underestimate the number of prey swallowed if the system is used in the wild. In the oesophagus temperature recordings, the magnitude of drops was weakly, but positively, correlated to the mass of single, ingested prey (R super(2) = 0.40).

  62. African Penguins Spheniscus demersus along the KwaZulu-Natal coast, 1981-1999

    C. P. Wilkinson, DA Esmonde-White, L. G. Underhill and P. A. Whittington.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 111-113.

    The African Penguin is rare east of Algoa Bay, Eastern Cape, South Africa. Ninety-nine penguins were found onshore along the coast of KwaZulu-Natal in 1981-1999, mostly in a state of starvation. Of these, 77% were between June and October during, and immediately after, the 'sardine run' of Sardine Sardinops sagax; 95% of birds that were aged were first-year birds; 96% were in the southern half of KwaZulu-Natal, south of Mtunzini (29 degree S) where the sardine run is strongest. The observations suggest that juvenile penguins from the nearest breeding colonies, in Algoa Bay, are drawn eastwards by the migrating Sardines; when these shoals dissipate, a lack of food leads to them coming ashore.

  63. Changes in depth utilization in relation to the breeding stage: a case study with the King Penguin Aptenodytes patagonicus

    J-B Charrassin, C-A Bost, K. Puetz, J. Lage, T. Dahier and Y. Le Maho.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 43-47.

    The impact of breeding constraints on foraging strategies of penguins has been poorly studied. We examined during two years the foraging behaviour of King Penguins Aptenodytes patagonicus during the incubating, brooding and creching periods at the Crozet Islands, southern Indian Ocean. In this species, the non-synchronized breeding cycle makes possible the simultaneous study of foraging behaviour at two breeding stages, thus allowing a comparison of different foraging activities at constant food availability. Diving behaviour was assessed using time-depth recorders. When compared with birds with eggs, birds at the brooding stage dived deeper and spent more time at greater depth in summer, whereas their foraging trip duration was halved. In autumn, foraging trip duration, depth attained and diving frequency to depth >100 m for birds with small and large chicks were generally greater than those observed in birds foraging in summer. The significance of these changes is discussed with respect to breeding requirements and food availability.

  64. Daily nest attendance and breeding performance in the Little Penguin Eudyptula minor at Phillip Island, Australia

    A. F. Chiaradia and K. R. Kerry.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 13-20.

    The daily attendance patterns of Little Penguins Eudyptula minor were investigated for 55 nests on Phillip Island, Australia during the pre-breeding (winter), egg-laying, incubation and guard periods of the 1995/96 season. Birds were identified by transponder tags which were subcutaneously implanted between the scapulae. Males spent significantly longer in the colony (15 days) than did females (11 days) before egg laying. Both males and females remained ashore for 5.0 days over their laying period. Eggs were incubated for 35.5 days (range 31-40 days, n = 48 nests). Incubation shifts lasted 3.4 days on average and the number of foraging trips averaged 5.6 trips per bird. After hatching parents guarded their chicks for a total of 14.5 days. Successful parents started breeding earlier, had shorter incubation shifts and undertook more foraging trips than did failed birds during both incubation and chick-guard periods. The later a Little Penguin started to breed the poorer was its breeding performance.

  65. Decrease of African Penguins at the Possession Island group, 1956-1995: Contrasting trends for colonial and solitary breeders

    I. Cordes, RJM Crawford, A. J. Williams and B. M. Dyer.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 129-138.

    Between 1956 and 1995, the African Penguin Spheniscus demersus population at Possession Island decreased by 96% from 23 245 breeding pairs to 895 pairs. At adjacent North Reef, African Penguins ceased breeding before December 1988. In 1956, 850 pairs bred there. At Possession Island, 22 441 pairs of penguins bred colonially in 1956, but there were only 360 pairs in colonies in 1995 – a decrease of 98%. By contrast, there were 804 solitary breeding pairs in 1956 and 535 in 1995 – a decrease of 33%. All colonies at the southern portion of Possession Island and that at North Reef were abandoned by 1986. In the central and northern portions of Possession Island colonial breeding still persists, but as numbers have decreased colonies have fragmented. Minimal recruitment to the breeding population, probably resulting from food scarcity, is considered the most likely reason for the long-term decrease in penguin numbers. When penguins were abundant, there were insufficient suitable sites for solitary breeding and most birds bred in large colonies. Sites used by solitary breeders provide shade and restrict access by predators. Colonial breeding may have facilitated sharing information on the distribution of, and group foraging on, Sardine Sardinops sagax, the main food of penguins off Namibia in the 1950s.

  66. Diving behaviour of Humboldt Penguins Spheniscus humboldti in northern Chile

    G. Luna-Jorquera and B. M. Culik.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 67-76.

    The Humboldt Penguin Spheniscus humboldti is an endangered species whose population is decreasing over its whole distributional range. In support of conservation efforts, systematic studies are being conducted on the ecology and behaviour of these birds at sea. Time-depth recorders were used to investigate the foraging behaviour of Humboldt Penguins at Isla Pan de Azucar (26 degree S, 72 degree W), northern Chile, during the breeding seasons of 1994/95 and 1995/96. A four-channel logger (MK6, Wildlife Telemetry) equipped with speed, depth, temperature and light-intensity sensors was used to obtain information from 20 foraging trips of 12 penguins, amounting to a total of 301 hours of swimming consisting of 11 011 dives. Birds departed from the colony between 06h00 and 09h00 and returned mainly between 15h00 and 23h00. Distance travelled was strongly correlated with total time spent at sea. Maximum dive depth was 53 m around mid-day when light intensity was maximal. At night maximum depth attained was 12 m. Maximum dive depth was positively correlated with dive duration (r = 0.80), as well as with descent and ascent angle (r = 0.78), and descent and ascent rate (r = 0.86). Dives to between 0.5 and 3 m were interpreted as travelling dives and had a mean depth of 1.6 m. All dives deeper than 3 m were regarded as foraging dives with a mean depth of 11.5 m. Mean dive durations during travelling and foraging were 18.4 s and 47.9 s, respectively. Mean swim speed during travelling was 1.7 m.s super(-1). Overall speed during foraging dives (descent, bottom and ascent) was 1.9 m.s super(-1).

  67. Fidelity to nest site and mate in Fiordland Crested Penguins Eudyptes pachyrhynchus

    CC St Clair, I. G. McLean, JO Murie, S. M. Phillipson and BJS Studholme.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 37-41.

    Fiordland Crested Penguins Eudyptes pachyrhynchus are the least gregarious of the crested penguins, breeding in caves, burrows, and under dense vegetation along the coast of Fiordland, New Zealand. A population on Open Bay Island was monitored, with varying degrees of intensity, from 1988 to 1995. During this period, 175 adults were banded in three semi-contiguous areas and their returns of 46 mapped nest sites were recorded. In 1989, reproductive success to the creche stage was also known. Return rates (used here as minimum annual survival estimates) ranged from 53-83% with means of 71% for both sexes. Mean nest fidelity averaged 76% for males and 72% for females with slightly lower values for mate fidelity (64% for males, 62% for females). Neither of these parameters differed significantly between the sexes. In 1989, penguins of both sexes that returned to a 1988 nest site exhibited higher reproductive success than those that nested at a new site. A similar, but non-significant, trend was apparent for mate fidelity. By contrast, reproductive success in 1989 did not result in a higher likelihood of returning to the same nest or mate in 1990. Females were more likely to 'separate' (i.e. mate infidelity when both members of the previous pair were present) than males (33% vs. 13%) and both sexes were more likely to separate if they had previously failed to raise a chick. Fifteen cases of mate switching occurred within years and all but one involved two females and a single male. Three of these followed the return of a male's previous mate. We compare these patterns to similar published data for other bird species and discuss their conservation implications.

  68. Foraging areas of King Penguins Aptenodytes patagonicus breeding at Possession Island, southern Indian Ocean

    K. Puetz, Y. Ropert-Coudert, J-B Charrassin and R. P. Wilson.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 77-84.

    Between January and March 1994 and between January and June 1995 we used Global Location Sensors (GLS) to determine the feeding areas of King Penguins Aptenodytes patagonicus breeding at Possession Island, Crozet Archipelago. In both years, the preferred feeding area during summer was located about 300 km south of the island, being slightly more distant in 1995. Mean foraging trip duration was 5.7 plus or minus 1.1 days (n = 6) during summer 1994 and 8.9 plus or minus 3.7 days (n = 9) during summer 1995, respectively. During summer the travelling speed of the King Penguins studied was highest at the first and last days of the foraging trip (c. 8 km/h). During the middle days of foraging trips travelling speeds were much lower (< 5 km/h). In early winter, between late April and mid-June 1995, two King Penguins equipped with GLSs executed foraging trips with durations of 53 and 59 days, respectively. Both birds travelled beyond 60 degree S with maximum distances to the colony of 1600 and 1800 km, respectively, and total distances covered of about 5000 km. The winter trips were characterized by alternating periods of higher and lower distances covered, indicating a highly variable feeding success at different localities. The relationships between foraging trip duration (days) and maximum distance to the colony (km) and total distance covered (km) were calculated to be maximum distance = 210 + 27 d and total distance = 340 + 85 d.

  69. Foraging behaviour of the Chinstrap Penguin Pygoscelis antarctica at Ardley Island, Antarctica

    R. P. Wilson and G. Peters.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 85-95.

    The foraging behaviour of 20 Chinstrap Penguins Pygoscelis antarctica breeding at Ardley Island, King George Island, Antarctica was studied during the austral summers of 1991/2 and 1995/6 using stomach temperature loggers (to determine feeding patterns), depth recorders and multiple channel loggers. The multiple channel loggers recorded dive depth, swim speed and swim heading which could be integrated using vectors to determine the foraging tracks. Half the birds left the island to forage between 02h00 and 10h00. Mean time at sea was 10.6 h. Birds generally executed a looping type course with most individuals foraging within 20 km of the island. Maximum foraging range was 33.5 km. Maximum dive depth was 100.7 m although 80% of all dives had depth maxima less than 30 m. The following dive parameters were positively related to maximum depth reached during the dive: total dive duration, descent duration, duration at the bottom of the dive, ascent duration, descent angle, ascent angle, rate of change of depth during descent and rate of change of depth during ascent. Swim speed was unrelated to maximum dive depth and had mean values of 2.6, 2.5 and 2.2 m/s for the descent, bottom and ascent phases of the dive. The sequence of maximum depths reached in a dive series was not random, tending to be concentrated at a particular depth, irrespective of whether the penguins were feeding at that depth or not. Generally, sequential dives to a specific depth were abruptly terminated by a single dive to another depth which was characteristic in having no bottom phase and unusually steep descent and ascent angles. The maximum depth reached during this dive was then adhered to in the next dive sequence. There were peaks in feeding activity between 06h00 and 09h00 and 14h00 and 22h00. Although foraging effort and relative success decreased around midnight when light intensity was lowest, birds did dive up to 22 m at this time, considerably deeper than sympatric Adelie P. adeliae or Gentoo P. papua Penguins. These findings indicate that, in accordance with their small body size, Chinstrap Penguins forage inshore close to the surface during the chick-rearing phase. Apparent short-comings in the volume of water searched compared to sympatric congeners can be made good by intense diving activity during the period at sea, with no inter-bout rests, higher swim speeds and an apparent ability to be able to forage at lower light intensities which enables Chinstrap Penguins to forage better under twilight conditions.

  70. Foraging range of the Yellow-eyed Penguin Megadyptes antipodes

    P. J. Moore.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 49-58.

    Foraging ranges of Yellow-eyed Penguins Megadyptes antipodes were estimated off the south-east coast of the South Island, New Zealand during three breeding seasons, 1990/91, 1991/92 and 1992/93. Transmitters were glued to penguins and their foraging locations were estimated by triangulation of radio bearings to two land-based receiving stations. At the main study area - Boulder Beach on the Otago Peninsula - 14 penguins were radio-tracked for two- to three-week periods during three stages of the breeding seasons. Birds at Otago Peninsula foraged over the continental shelf, which is mostly 40-80 m deep and 30 km wide. Foraging time was also measured using dive recorders during the 1993/94 and 1994/95 breeding seasons. The median foraging trip over the five years that recordings were made was 14 hours (range two hours to seven days) and birds travelled a median of 13 km (up to 57 km) from the breeding area. The longer, more distant trips took place during the incubation period, except during 1992/93, when trips were of relatively shorter duration and distance. Failed breeders and nonbreeders travelled farther (females) and for longer (especially males) than breeding birds. Breeding birds that later failed took longer trips during incubation than successful breeders, and females of the former category also travelled farther. Foraging patterns during the postguard period at Long Point were similar to Boulder Beach, although foraging trips were shorter as some birds went to sea two-three times per day. Individuals showed different, although usually overlapping, foraging ranges and retained these patterns at different times of the breeding season and in different years. Some birds were markedly inshore feeders, with centres of activity 16 km from the coast. Breeding success, and possibly foraging time and range was affected by disturbance. Breeding success of birds carrying packages and diet sampled was lower than average, but not as low as birds that were diet sampled only.

  71. Heat Transfer Through Penguin Feathers

    C. Dawson, J. F. Vincent, G. Jeronimidis, G. Rice and P. Forshaw.

    Journal of theoretical biology, Vol. 199, No. 3, Aug 7, 1999, pp. 291-295.

    Morphological measurements of penguin feathers are used to construct a thermal model of heat transfer through the coat. Assuming uniform distribution of the feathers and their associated afterfeathers, it is possible to model heat transfer through the coat of the penguin using standard theory. It is shown that convection does not occur in the coat of the penguin and that radiative heat loss is minimized. The theory predicts a thermal conductivity of 2.38 W m super(-2)K super(-1)which compares well with an empirically measured value of 1.93 W m super(-2)K super(-1).

  72. Nest-site selection by Yellow-eyed Penguins Megadyptes antipodes on grazed farmland

    R. McKay, C. Lalas, D. McKay and S. McConkey.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 29-35.

    The viability of Yellow-eyed Penguins Megadyptes antipodes on South Island, New Zealand, is threatened through the loss of breeding habitat by land clearance and the loss of chicks to introduced predatory mammals. Penguin nests at Papanui Beach, Otago Peninsula, were spread through about 7 ha of grazed grassland and shrubland. Here farming and Yellow-eyed Penguin conservation were shown to be compatible through active management: the impact of farm stock was minimised by excluding cattle; predation was minimised by trapping; and disturbance by humans and dogs was minimised by prohibiting public access. Penguin nest sites varied from sites with total lateral concealment and overhead cover to fully exposed sites. Deaths attributed to avian malaria decimated the breeding population of 21 pairs in early 1990. Nest numbers recovered to 21 by the 1995/96 season but their distribution had changed. Nests lacking overhead concealment in grassland habitat increased from two (10%) in 1989/90 to 12 (57%) in 1995/96. Unexpectedly the new generations of breeders appeared to select open, relatively exposed sites in grassland in preference to sites in dense vegetation offered by shrubland. We have not yet found an explanation for this preference. However, a relatively large number of non-breeders congregated at pastures near the sea in the 1995/96 season with the vast majority in grassland rather than shrubland. The presence of clear areas may be important for the recruitment of breeders at this location.

  73. Penguins: Paradoxes and patterns

    J. P. Croxall and L. S. Davis.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 1-12.

    Penguins are often considered to be as ecologically and behaviourally homogenous as their morphology. Their structural morphology and associated physiological adaptations are governed by the demands of operating as flightless, subsurface marine predators. However, within the very strict constraints of this life-form, penguins show considerable ecological and behavioural heterogeneity, although some of this undoubtedly relates to the range of latitudes and biotopes in which penguins breed. In this paper we: (i) briefly summarise and review some of the main features of the breeding biology, ecology and demography of penguins; (ii) identify consistent patterns across species in the grouping of these features – and highlight anomalies; (iii) suggest explanations/hypotheses for some of the potential links between ecology, behaviour and demography within these groupings; (iv) investigate six topics containing potential paradoxes, namely: migration, fasting, mate fidelity, brood reduction, demography and duration of breeding seasons. We conclude that in many biological and ecological traits penguins can be divided into two groups: (i) resident species, feeding inshore with short fasts ashore, breeding at an early age and having low divorce rates, and; (ii) migrant species, feeding offshore with long fasts ashore, breeding at older ages and having higher divorce rates. The placement of Magellanic Spheniscus magellanicus and Gentoo Pygoscelis papua Penguins in opposite groups to their congeners is particularly intriguing. We suggest that trade-offs between the year-round abundance and predictability of prey and the latitudinally-influenced time available for breeding are important determinants of these patterns. Considerably improved basic biological and ecological data on penguins and careful testing of explicit hypotheses will be required to investigate further both the suggested patterns and the remaining paradoxes.

  74. Pick up a penguin for hints on how to survive the cold

    Anonymous

    Professional Engineering, Vol. 12, No. 18, Oct 6, 1999, pp. 46.

    How penguins survive their harsh lifestyle is the subject of research at the Defence Clothing and Textiles Agency. The answer, according to DCTA researcher Colin Dawson, is in the construction of penguin's feathers. Penguins have only one type of feather and they are particularly tightly packed.

  75. Population dynamics of the African Penguin Spheniscus demersus at Robben Island, South africa

    RJM Crawford, L. J. Shannon and P. A. Whittington.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 139-147.

    African Penguins Spheniscus demersus recolonized Robben Island in 1983 when about nine pairs bred at the island. By 1996, the colony had grown to about 3100 pairs. Adult survival was probably between 0.82 and 0.90 in 1993/94, but fell to 0.75 in 1994/95 when many birds at the island were oiled following the sinking of the Apollo Sea in June 1994. Some penguins initiated breeding when two years old, and all were assumed to be breeding at age five. The proportion of mature birds that bred in a year varied between about 0.70 and 1.00. During a breeding season, pairs laid their first clutches between January and August, mostly in February and March. The average clutch was 1.86 eggs. Of lost clutches 32% were replaced, whereas 23% of pairs losing broods relayed and 21% of pairs that successfully fledged chicks relayed. On only one occasion was the laying of a third clutch during a breeding season recorded, and this was unsuccessful. The mean number of chicks fledged per breeding pair varied between 0.32 and 0.59 per annum. Both fledging success and immigration of immature birds to the colony were significantly related to the spawner biomass of Cape Anchovy Engraulis capensis, the most important prey item of penguins at the island. Growth of the colony has been driven by immigration. Depending on the values assumed for survival of adults and first-year birds, 59-87% of new adults in the colony resulted from immigration. Several birds banded as chicks at Dassen and Dyer islands were recorded breeding at Robben Island.

  76. Predator identification from bite marks on penguin and albatross chicks

    H. Ratz, H. Moller and D. Fletcher.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 149-156.

    Ferrets Mustela furo, Stoats M. erminea and feral House Cats Felis catus are introduced predators in New Zealand that threaten many nesting seabirds and other native species. Fifty-one Yellow-eyed Penguin Megadyptes antipodes chicks, four Royal Albatross Diomedea epomophora chicks and one Little Penguin Eudyptula minor adult underwent necropsy. Four Yellow-eyed Penguin chicks, three Royal Albatross chicks and the Little Penguin had puncture holes in their skin from predator bites. Three Royal Albatross chicks also had markings on their bills that were analysed separately. Only three outlying puncture hole pairs could be matched unequivocally with the species-specific inter-canine distance of each predator species. Most bites were clustered so that separate bites could not be discerned. One Yellow-eyed Penguin chick and two Royal Albatross chicks were preyed on by Stoats, but the culprits responsible for the deaths of the other 21 dead birds could not be definitely determined. There are many logistical problems and unquantified assumptions in other methods of identifying predators and in several unquantified claims that predator identity is known. Development of better diagnostics to identify predators would help conservation management by allowing better targeting of predator trapping and poisoning efforts.

  77. Shipboard observations of penguins at sea in the Australian Sector of the Southern Ocean, 1991-1995

    T. A. Reid, CL Hull, D. W. Eades, R. P. Scofield and E. J. Woehler.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 101-110.

    Locations of penguins at sea were recorded during systematic observations carried out on voyages between Hobart, Tasmania and Antarctica during 1991-1995. Two types of voyages were undertaken: five World Ocean Circulation Experiment (WOCE) cruises along longitude 140 degree E; and two Antarctic and Heard Island exploratory fishing / re-supply voyages between Hobart, Heard Island and the Australian Antarctic Territory. Observations were carried out to describe the distribution of seabirds, including penguins, at sea. In this paper penguin distribution has been described, along with an analysis of environmental variables associated with the sightings, and an attempt was made to use these variables to predict penguin distribution. Ten species were observed: Emperor Aptenodytes forsteri, King A. patagonicus, Adelie Pygoscelis adeliae, Gentoo P. papua, Macaroni Eudyptes chrysolophus, Royal E. schlegeli, Rockhopper E. chrysocome, Snares Crested E. robustus, Fiordland Crested E. pachyrhychus and Little Eudyptula minor Penguins. The sightings of Snares Crested and Fiordland Crested Penguins were unique in the sector covered. Juvenile and adult Emperor, Adelie and Macaroni Penguins were found in different sectors of the Southern Ocean. Latitude, longitude, depth of water, salinity, sea surface temperature, ice cover and icebergs were recorded. Cluster analysis was used to predict penguin distribution, and compiled three groups. A discriminant function analysis revealed only moderate success in the allocation of species to these groups. This probably arose because: 1. the environmental variables measured were not good indicators of penguin distributions at sea; 2. the sightings of penguins were probably not always at foraging grounds, and penguins may have been en route to foraging zones when observed; 3. the patterns of penguin distribution are not predictable at the scale of analysis because they respond opportunistically to regions around their breeding sites; 4. penguins are not congregating at specific areas.

  78. The Species of Penguins and Penguins Occurring in the Vicinity of King Sejong Station

    S-K Chang.

    Ocean Research, Vol. 21, No. 2, Dec 1999, pp. 137-147.

    Penguins are one of the key constituent organisms in the Antarctic ecosystem. A total of 18 species of penguins occur only in the southern hemisphere from the Galapagos Archipelago to southern area off Australia and New Zealand, South Africa, South America, and the islands scattered in the Southern Ocean to the coast along the Antarctic Continent. In the Antarctic Treaty area, there are only 5 species of penguins such as Emperor (Aptenodytes forsteri), Gentoo (Pygoscelis papua ellsworthi), Adelie (P. adeliae), Chinstrap (P. antarctica), and Macaroni (Eudyptes chrysolophus) penguins. Two additional species, the King (Aptenodytes patagonicus patagonicus) and Rockhopper (Eudyptes chrysocome) penguins, however, are distributed within the Antarctic Convergence. In the vicinity of King Sejong Station located in King George Island, the South Shetland Islands off the Antarctic Peninsula, 5 species are observed, among which 2 Pygoscelis species such as the Gentoo and Chinstrap penguins hatch their eggs and raise their chicks at the rookery 2 km south of King Sejong Station in summer. Adelie penguins hatch their chicks in other place in King George Island. One Emperor penguin roamed on the frozen Maxwell Bay which has been frozen every two or three years with the approximate thickness of 60 cm. And one Macaroni penguin also visited the rookery in summer. We should carry out researches on the penguins occurring in the vicinity of King Sejong Station to monitor the environmental changes around King Sejong Station and the South Shetland Islands.

  79. Stomach stones from Emperor Penguin Aptenodytes forsteri colonies in the Weddell Sea

    J. Splettstoesser and F. S. Todd.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 97-100.

    More than 300 hundred stones collected at three Emperor Penguin Aptenodytes forsteri breeding colonies in the Weddell Sea were examined to ascertain their composition and provenance. The movements of stones carried by glaciers is discussed with special reference to the movement of glaciers in Antarctica. The function of stomach stones is also reviewed.

  80. Temporal and spatial variation in breeding success of the little Penguin Eudyptula minor on the east coast of Australia

    M. Fortescue.

    Marine Ornithology, Vol. 27, Mar 1999, pp. 21-28.

    A 10-year study of the Little Penguin Eudyptula minor on Bowen Island has revealed comparatively high breeding success for this large colony towards the northern limit of the species' range. Similarly high success has been found at nearby Lion Island. The colony is prone to episodic broad-scale changes of ocean and climate, including the global-scale El Nino Southern Oscillation (ENSO). These climatic changes influence to varying degrees the breeding success of colonies on the east coast of Australia. The mean breeding success for first broods of the Bowen colony was 1.23 chicks/pair. This is the highest recorded for the species, and 20% of pairs lay second broods in the same season. Lion and Bowen Islands are characterised by distinctive native vegetation assemblages which provide high quality, formally protected, nesting habitat for penguins, and a marine environment predominantly influenced by the East Australia Current, contributing to higher breeding success. Reduced foraging range of Bowen Island penguins during critical stages of the breeding cycle compared with other colonies in the south suggest regional oceanographic characteristics may influence distribution of major diet items. There appears to be an inverse relationship between breeding success and latitude of breeding colonies. This study is continuing, and early results are presented.

  81. Ammonium in coastal Antarctic aerosol and snow: Role of polar ocean and penguin emissions

    M. Legrand, F. Ducroz, D. Wagenbach, R. Mulvaney and J. Hall.

    Journal of Geophysical Research.D.Atmospheres, Vol. 103, No. D9, May 1998, pp. 11-11,056.

    Year-round aerosol samples collected in the boundary layer at coastal Antarctic sites (Dumont D'Urville, Neumayer, and Halley) indicate a seasonal cycle of ammonium concentrations with a minimum in winter (April-September). A large intersite difference appears in the summer (November-February) maxima values, from similar to 12.5 ng m super(-3) at Neumayer to 140-230 ng m super(-3) at Dumont D'Urville. At Dumont D'Urville, ammonium concentrations are the largest ever reported from Antarctic sites, and the large summer maxima are associated with large enrichments with respect to sea salt for potassium and calcium. In addition, seasonal ammonium variations at Dumont D'Urville are in phase with a well-marked seasonal cycle of oxalate concentrations which exhibit maxima of 5-10 ng m super(-3) in spring and summer and minima of less than 0.5 ng m super(-3) in winter. Such a composition of aerosols present in the boundary layer at Dumont D'Urville in summer is linked to the presence of a large Adelie penguin population from the end of October to March at the site. Ornithogenic soils (defined as guano-enriched soils), together with the bacterial decomposition of uric acid, are a source of ammonium, oxalate, and cation (such as potassium and calcium) aerosol, in addition to a subsequent large ammonia loss from ornithogenic soils to the atmosphere. The total breeding population of 5 million Adelie penguins widely distributed around the Antarctic continent may emit, at most, some 2.5x10 super(-4) Mt of NH sub(3)-N during the summer months. In contrast, Halley and Neumayer Stations are far less exposed to penguin colony emissions. At Neumayer, ammonium concentrations peak from January to March and are in phase with the increase of biogenic sulfur species. Here the NH sub(4) super(+)/(MSA + nss SO sub(4) super(-)) molar ratio is close to 13% in summer aerosol and to 40% in winter aerosol. Using this summer ratio, which may be related to ammonia and sulfur oceanic emissions occurring south of 50 degree S in summer and estimated DMS emissions in these regions at this time, we derive an upper limit of 0.064 Mt NH sub(3)-N emitted per year by the high-latitude Southern Ocean in summer. This study indicates a very limited ammonia neutralization of acidic sulfate aerosols at high southern latitudes, except in the vicinity of ornithogenic soils occupied by large penguin colonies.

  82. Hypothermia in foraging king penguins

    Y. Handrich, R. M. Bevan, J-B Charrassin, P. J. Butler and et al.

    Nature, Vol. 388, No. 6637, Jul 3, 1997, pp. 64-67.

    Researchers show that the abdominal temperature of king penguins may fall to as low as 11 degrees C during sustained deep diving. The slower metabolism of cooler tissues resulting from physiological adjustments associated with diving could explain why penguins and possibly other marine animals can dive for long durations.

  83. Rare white penguin puzzles scientists

    Anonymous

    Current science, Vol. 83, No. 1, Sep 5, 1997, pp. 13.

    An all-white emperor penguin has been discovered at Terra Nova Bay Antarctica. The rare penguin is the first and only one of its kind to be found.

  84. The seal's own skin game

    Gordon S. Court.

    Natural History, Vol. 105, No. 8, Aug 1996, pp. 36.

    Leopard seals prey on Adelie penguins in Antarctica. The leopard seal's diet and hunting techniques are examined.

  85. Aspects of the feeding ecology of emperor penguins (Aptenodytes forsteri) and king penguins (Aptenodytes patagonicus)

    K. Puetz.

    Acta Palaeontologica, Vol. 56, No. 2, 1994, pp. 269-277.

    Aspects of the foraging ecology of emperor (Aptenodytes forsteri) and king penguins (Aptenodytes patagonicus) were examined using different methodologies. The foraging ecology of king penguins was elucidated at the onset of, and at the end of, the breeding period using stomach temperature sensors and externally-attached activity recorders. The exact time at which feeding activity took place, as well as the amount ingested, could be ascertained using the stomach temperature sensors. The activity recorders logged information on dive depth, swim direction, swim speed, water temperature and light intensity. Consideration of these parameters elucidated the types of activity in which king penguins engaged at sea and demonstrated the extent to which such behaviour was dependent on biotic and abiotic variables.

  86. Causes of nest desertion during incubation in the Magellanic penguin (Spheniscus magellanicus)

    P. Yorio and P. D. Boersma.

    Condor, Vol. 96, No. 4, 1994, pp. 1076-1083.

    We quantified the causes and rate of nest desertions in Magellanic Penguins (Spheniscus magellanicus) during the egg stage at Punta Tombo, Argentina. Incubating Magellanic Penguins rarely deserted. The average desertion rate during seven years was 11% (SD = 9.2%). Desertions were poorly correlated with the length of the incubation spell and only 25% of the desertion could be accounted for by delayed nest relief. Body condition at the start of the incubation spell appears to be the most important factor in determining desertions. Penguins that deserted were lighter for their body size at the time of egg laying than penguins that did not desert. Desertion was significant and common during the first part of incubation, the time when females are present. Flooded nests were more likely to be deserted than nonflooded nests, but desertions from flooding were few. High temperatures did not increase desertion during incubation, thus it is unlikely that heat stress is an important cause of nest desertion. An individual's body condition appears to be the most important factor in explaining desertion but behavior of the mate and other factors can play a role.

  87. Predation on Gonatus antarcticus by Falkland Islands seabirds

    K. R. Thompson.

    Antarctic science, Vol. 6, No. 2, 1994, pp. 269-274.

    Recent studies of Falkland Islands seabird diets have found that Gonatus antarcticus is a major prey item for a number of penguin species. Rockhopper (Eudyptes chrysocome), gentoo (Pygoscelis papua) and Magellanic (Spheniscus magellanicus) penguins breeding in the Falklands are estimated to consume several thousand million Gonatus per annum, with mean dorsal mantle lengths of 28-42 mm. Aspects of the distribution and growth of the G. antarcticus stock in the vicinity of the Falkland Islands are discussed.(DBO)

  88. Squid diet of emperor penguins (Aptenodytes forsteri) in the eastern Weddell Sea, Antarctica during late summer

    U. Piatowski and K. Putz.

    Antarctic science, Vol. 6, No. 2, 1994, pp. 241-247.

    The data presented provides new information on the distribution of Antarctic squids and on the summer diet of the emperor penguins. The diet of 58 adult emperor penguins (Aptenodytes forsteri) on the fast ice of the Drescher Inlet, Vestkapp Ice Shelf (72~'52'S, 19~'25'W) in the eastern Weddell Sea was investigated. Prey consisted principally of squid, fish, krill, amphipods and isopods. Squids were identified by the lower beaks and allometric equations were used to estimate the squid biomass represented. Beaks occurred in 93% of the stomach samples. Each sample contained a mean of 27 beaks (range 1-206). Ninety-two percent of the squids could be identified by the lower beaks and belonged to four families (Onychoteuthidae, Psychroteuthidae, Neoteuthidae and Gonatidae). The most abundant squid was Psychroteuthis glacialis which occurred in 52 samples with lower rostral lengths (LRL) ranging from 1.4-7.2 mm. Forty-five samples contained Alluroteuthis antarcticus (LRL range 1.8-5.8 mm), 17 Kondakovia longimana (LRL range 4-12.1 mm), and four Gonatus antarcticus (LRL range 4.1-6.1 mm). In terms of biomass K. longimana was the most important species taken by the penguins comprising 50% of total estimated squid wet mass (245358 g) in 1990 and 48% in 1992 (154873 g). However, if only fresh beaks were considered for estimations of squid consumption, i.e. beaks that have been accumulated for not longer than 5-6 days in the stomachs, squid diet was of minor importance. Then total squid wet mass accounted for only 4809 g in 1990 and 5445 g in 1992 which implies that one penguin took c. 30 g squid d super(-1) with P. glacialis and A. antarcticus being the most important by mass. The prey composition suggest that emperor penguins take squid at the steep slope regions of the eastern Weddell Sea.(DBO)

  89. Concentration of selected metals in penguins and other representative fauna of the Antarctica

    P. Szefer, J. Pempkowiak, B. Skwarzec, R. Bojanowski and E. Holm.

    Science of the Total Environment, Vol. 138, No. 1-3, 1993, pp. 281-288.

    Concentration of Zn, Cu, Cd, Pb, Ag, Co, Ni, Cr, Mn and Fe were determined in muscle and liver of three species of penguins and other animals of the antarctic region. Liver was characterized by maximum concentrations of all the metals analyzed. The element levels in the samples assayed are in keeping with those reported previously by other authors. It is assumed that specific food habits of penguins are mainly responsible for elevated Cd levels in livers of these birds.

  90. The use of an automated weighing and recording system for the study of the biology of Adelie penguins (Pygoscelis adeliae)

    K. Kerry, J. Clarke and G. Else.

    Proceedings of the NIPR Symposium on Polar Biology. Tokyo, No. 6, 1993, pp. 62-75.

    A system that automatically weighs, identifies and determines the direction of penguins moving between their breeding colony and the sea is described. Data obtained from it for a complete colony (589 nets from which 412 chicks were fledged) and related to the foraging ecology of the Adelie penguin Pygoscelis adeliae are presented for the period hatching to fledging. These were obtained at Bechervaise Island (total Adelie penguin population 1816 nests) near Mawson Station, Antarctica during the 1991/92 breeding season. The system logged more than 80,000 penguin crossing over a period of three months. Results showed that from hatching (20 December-10 January) onward males and females deliver a similar mass of food to the chick per visit despite males being approximately 480 g (11.5%) heavier when empty. A mass of 45 kg was delivered to the colony for each chick raised to fledging. The average fledging weight was 3.1 kg. The value of the system for large scale data collection in long term monitoring and biological studies is discussed.

  91. Reproductive and foraging energetics of high latitude penguins, albatrosses and pinnipeds: Implications for life history patterns

    D. P. Costa.

    American Zoologist, Vol. 31, No. 1, 1991, pp. 111-130.

    Pinnipeds and seabirds feed at sea, but are tied to shore to rear their young. Such a fundamental life history constraint should lead to convergent adaptations in foraging and reproductive ecology. However, intrinsic differences in mammalian and avian reproductive biology may limit the potential for convergence. In this paper I examine both reproductive and foraging energetics of pinnipeds and seabirds. This is done in an attempt to identify traits that might be considered convergent adaptations to life in the marine environment and to show how divergent life history patterns are optimal for different reasons. From this analysis we find that seabirds invest a greater total amount of energy and protein into the offspring than pinnipeds, but this comes at the cost of making more trips to sea. Whereas pinnipeds forage in a manner more consistent with the predictions of central place foraging theory and exhibit a greater ability to compensate to the shortened breeding season typical of high latitude environments.

  92. Melioidosis in a macaroni penguin Eudyptes chrysolophus

    K. MacKnight, D. Chow, B. See and N. Vedros.

    Diseases of aquatic organisms, Vol. 9, No. 2, 1990, pp. 105-107.

    A female macaroni penguin Eudyptes chrysolophus , at Ocean Park, Hong Kong, died suddenly during a period of extremely high ambient temperature and humidity. Necropsy results including pathological, histological, and microbiological observations indicated that the penguin died due to disseminated Pseudomonas pseudomallei infection. This is the third report of this disease in avian species, and the first report involving a penguin.

  93. The use of analysis of penguin stomach contents in simultaneous study of prey and predator parameters

    E. Marschoff and B. Gonzalez.

    Meet. of the Scientific Comittee and Working Groups of the CCAMLR, Hobart (Australia), 1989

    Size selectivity of krill by penguins is shown to be highly sensitive to the statistical assumptions made during the analysis of data. The nested ANOVA method is proposed as being the correct approach for analysis because lack of independence between krill specimens found in the stomach of a given penguin prevents the pooling of krill lengths from different samples. Samples taken in Bahia Esperanza were used to illustrate the different approaches to this analysis. A highly significant linear regression between krill size and time of sampling was found.

  94. Comparative breeding energetics of penguins at Macquarie Island and Heard Island

    R. P. Gales, B. Green, K. Newgrain and D. Pemberton.

    CORMORANT., Vol. 16, 1988, pp. 127.

    Macquarie and Heard Islands are located north and south respectively of the Antarctic Polar Front and are substantially different in their surrounding oceanographic characteristics. The energy requirements of free-living Gentoo Pygoscelis papua , Macaroni Eudyptes chrysolophus , Royal E. schlegeli and Rockhopper E. chrysocome Penguins were assessed during the breeding season, simultaneously at both locations during 1986/87, by means of isotope turnover techniques. The energy requirements of adults while incubating, brooding and foraging will be presented, as well as the energy requirements of chicks. Intraspecific and locational comparisons are discussed with respect to feeding ecology.

  95. Diet of little penguins, Eudyptula minor , from Penguin Island, Western Australia

    NI Klomp and R. D. Wooller.

    AUST.J.MAR.FRESHWAT.RES., Vol. 39, No. 5, Mar 1988, pp. 633-639.

    Between March 1986 and March 1987, the stomach contents of 236 little penguins (E. minor ) on Penguin Island, Western Australia, were obtained using an emetic. The 1392 prey items identified included 16 fish species, one squid and one prawn, but four fishes comprised most of the birds' diet. Hyperlophus vittatus was taken throughout the year, Sardinops neopilchardus and Hyporhamphus melanochir mainly in winter and Spratelloides robustus during spring/summer. The penguins are largely opportunistic in their foraging and their diet appears to be similar to the fish species caught locally by commercial bait fishermen.

  96. Evolutionary ecology and ethology of penguins; with special reference to the gentoo penguin

    C. Bost and P. Jouventin.

    CORMORANT., Vol. 16, 1988, pp. 121.

    Of all seabirds, penguins have evolved the most elaborate morphological adaptations to an oceanic existence. With the penguin family, however, ecological and behavioural heterogeneity exists between species and between populations. An interspecific comparison of penguins nesting inside burrows, on sand or icebank shows that breeding biology and behaviour may be adapted to very different constraints. Different populations of the same species likewise show adaptations to the particular constraints of their environment. The Gentoo Penguin Pygoscelis papua makes an interesting case study because of its wide geographical distribution and its extended laying period.

  97. The foraging ecology of spheniscid penguins

    R. Wilson and M. P. Wilson.

    CORMORANT., Vol. 16, 1988, pp. 137.

    The Humboldt Penguin Spheniscus humboldti , Magellanic Penguin S. magellanicus , Jackass Penguin S. demersus and Galapagos Penguin S. mendiculus inhabit tropical or temperate areas. There are few data on the foraging behaviour of nonbreeding birds, but nesting Spheniscus penguins feed almost exclusively on pelagic school fish such as sardines and anchovies. Penguins leave their breeding islands in the morning and return, after foraging, at dusk. Most foraging trips are one day but may extend up to five days when the birds have large chicks. Spheniscus penguins at sea occur most frequently as singletons with larger groups being exponentially less common. Penguins normally travel by swimming just below the water's surface at speeds between 7-9 km/h, interspaced with rests on the surface where they swim at c. 1,5 km/h. Almost all birds appear to forage inshore within 25 km of their breeding locality. When a school of fish is encountered, penguins in groups hunt cooperatively. The birds swim rapidly round the fish herding them into a dense, depolarized group. Individual penguins leave the encircling group to plunge through the fish below the school. Prey are caught and swallowed underwater while the birds continue circling.

  98. Predicting the swimming and diving behaviour of penguins from muscle biochemistry

    J. Baldwin.

    Hydrobiologia, 1988, pp. 255-261.

    Energy metabolism in the pectoralis and supracoracoideus muscles of seven species of penguins was investigated by determining muscle fibre diameter, myoglobin content, pH buffering capacity and the distribution and properties of lactate dehydrogenase isoenzymes. The penguins can be arranged as follows in order of increasing anaerobic capabilities of the muscles: little < rockhopper and royal < gentoo < Adelie, emperor and king. As a good correlation exists between muscle biochemistry and known diving behaviour of emperor, king, gentoo and little penguins, predictions can be made about the behaviour of species for which only the biochemical data are available. (DBO)

  99. The respective role of male and female in establishing nest-sites and pair-bonds in the Humboldt penguin at Emmen Zoo, The Netherlands

    C. J. Scholten.

    CORMORANT., Vol. 16, 1988, pp. 133.

    In Humboldt Penguins Spheniscus humboldti it seems to be the male who determines the location of the nest-site. Ecstatic displays are performed nearly always by males and are done a great deal in the immediate surroundings of the nest. When a change of nest-site occurs, the male sometimes starts giving ecstatics at the new nest-site a year or more before actual nesting occurs. It is mostly the male who brings the nesting material to the nest. The results obtained in the Zoo confirmed observations I have made in the wild. The female seems to be the one who is decisive concerning the matter of mate choice. That this seems likely I will try to explain from several case studies made in the Zoo: 1) a case where I could follow the process of becoming a pair very closely, 2) one case where a male had a relationship with two females and, 3) five cases where partner-changes occurred. Observations on what happened in the Zoo in times of a surplus of males and in times of a surplus of females seem to agree with the role of male and female as mentioned above.

  100. The use of thallium as a radioactive source in autoradiographic devices for penguins at sea

    N. J. Adams, R. P. Wilson and CAR Bain.

    Journal of Field Ornithology, Vol. 59, No. 1, 1988, pp. 43-45.

    Recently developed remote sensing devices have provided information on behavior of penguins at sea. The authors describe the use of thallium in autoradiographic devices that record the speed and distance travelled and may be used in remote areas or over extended periods of at least 24 d.

  101. Virological studies on adelie penguins

    F. J. Austin.

    CORMORANT., Vol. 16, 1988, pp. 120-121.

    In temperate regions many wild birds are asymptomatically infected with a number of different viruses including paramyxoviruses and influenza A viruses. Evidence on the extent of these infections and on the emergence of virus strains which are pathogenic for other species has led to the suggestion that birds represent a large natural reservoir of viruses from which strains which are pathogenic for other species emerge. If this is so then it is important in studying the ecology of these viruses and the relationship between virulent and avirulent strains to discover the extent to which viruses occur in birds in all regions, including those in the relative isolation of Antarctica. Samples were collected from Adelie Penguins Pygoscelis adeliae at Cape Bird on Ross Island and tested for viruses and for antibodies. There was no evidence of influenza virus infection in the population but paramyxovirus infection was demonstrated by virus isolation and the detection of specific antibodies.

  102. "Diving behavior and performance, with special reference to penguins"

    Seabirds: Feeding Ecology and Role in Marine Ecosystems

    G. L. Kooyman and R. W. Davis.

    Cambridge: Cambridge University Press, 1987, pp. 63-75

    There have been few studies of the diving behavior or swimming performance of seabirds and data for some species are available only form laboratory experiments. The main features of aquatic behavior and performance relate to dive depth and duration and swimming speeds. These are influenced by hydrodynamic properties, body oxygen stores and metabolic rates. The authors review what is known on these topics. Most work has been done on penguins, but comparisons with other aquatic birds will be made where information is available.

  103. Ecology and physiology of fasting in king penguin chicks

    Y. Cherel, J-C Stahl and Y. Le Maho.

    Auk, Vol. 104, No. 2, 1987, pp. 254-262.

    Captive King Penguin (Aptenodytes patagonica ) chicks can fast for 5 Mo. during the subantarctic winter with a 70% decrease in body mass. To investigate the adaptive value of this remarkable resistance to starvation, the authors compared captive chicks with free-ranging chicks in their colony at Possession Island, Crozet Archipelago. Overall chick mortality in the colony during the winter and subsequent spring was about 50%. Mortality was highest in October, 6 mo. after the beginning of the winter, and may be attributed mainly to starvation. The decrease in body mass in the free-ranging chicks was remarkably similar to that for captive birds. In both groups, three periods were characterized according to the observed changes in the daily decrease in body mass per unit body mass dropped during the first period (I) of 5-6 days, was minimum and steady during period II, which lasted about 4 months, and increased in period III. Blood analysis of the captive chicks indicated the three periods correspond to modifications in protein breakdown.

  104. "The food and feeding ecology of penguins"

    Seabirds: Feeding Ecology and Role in Marine Ecosystems

    J. P. Croxall and G. S. Lishman.

    Cambridge: Cambridge University Press, 1987, pp. 101-131

    1987Particularly in the Southern Ocean, the abundance of penguins, coupled with their large biomass and high energy demands (swimming being more costly than the gliding flight typical of many of the other seabirds of the region), means that they play a major role in the avian community as consumers of marine resources. Penguins may comprise 90% of the bird biomass in Antarctic regions and are estimated to account for 76% of the food intake by birds in the Scotia Sea and 53% at South Georgia, despite forming only 13% of breeding numbers there. Given their potential importance in these (and many other) southern hemisphere areas, until very recently our information on their diet and feeding ecology was surprisingly sparse. This chapter reviews the available information on these topics and also examines the role of diet in the ecological segregation of sympatric penguins in the breeding season.

  105. Preliminary note on the extended laying period of the gentoo penguin Pygoscelis papua

    CA Bost.

    Alauda, Vol. 55, No. 4, 1987, pp. 287-292.

    In contrast to the majority of sub-Antarctic species, the Gentoo Penguin (Pygoscelis papua ) has a long laying season, especially in the Crozet archipelago. However, a detailed study on this locality has confirmed that the population here tend to promote breeding synchrony. The capacity of this penguin to overcome reproductive failure by re-laying seems to be the factor responsible for extending the laying season. A weak synchronisation for the first attempt at laying in a season is partly explained by a minority of birds having re-layed in – and therefore extended – the previous breeding season. The data and duration of laying varies with latitude to a degree which, in Antarctic regions, is unique to this species. The cause of this variability is suggested to be diverses selectives pressures, acting most forcibly at the northernmost breeding localities of the species distribution.

  106. Fasting and proteic catabolism in Antarctic penguins

    J. P. Robin, Y. Cherel and Y. Le Maho.

    Oceanis.Serie de documents oceanographiques.Paris, Vol. 12, No. 2, 1986, pp. 77-83.

    A reduction in protein catabolism is an essential mechanism in the physiological adaptation to prolonged fasting. It is important to understand this mechanism which can explain how many animals, particularly marine animals, tolerate long periods of fasting. Antarctic penguins, which fast for very long periods when breeding and moulting, are remarkable models for investigating changes in protein utilization. The authors have shown that these changes undergo three characteristic reversible phases. Variations in the rate of decrease in body mass or in the plasma concentration of uric acid may also be used as indexes for these protein changes.

  107. Plumage colour in pursuit-diving seabirds: Why do penguins wear tuxedos?

    D. K. Cairns.

    Bird Behavior, Vol. 6, No. 2, 1986, pp. 58-65.

    Relations among plumage type, feeding habitat, and air and water temperatures during the breeding season were examined for 61 species of pursuit-diving seabirds of the families Spheniscidae (penguins), Pelecanoididae (diving petrels), Alcidae (alcids) and Phalacrocoracidae (cormorants). Results suggest that plumage patterns of seabirds are adapted primarily to reduce the wearer's conspicuousness to prey. The dark backs possessed by all pursuit-diving seabirds may retard feather wear caused by solar radiation.

  108. Thermal adaptations in Subantarctic penguins during their passage to marine life

    H. Barre.

    Oceanis.Serie de documents oceanographiques.Paris, Vol. 12, No. 2, 1986, pp. 103-110.

    Adaptations were studied during simulated immersions with regard to thermal exchanges in the macaroni penguin (body mass: 2.3-3.4 kg) and in the king penguin (body mass: 8-10.5 kg). During the first immersion, the resting macaroni penguin chick was not able to maintain its homeothermy in a range of water temperature below 24 degree C. In the sea-acclimatized macaroni penguin, however, the increase in body insulation (+ 36%) and in the regulatory thermogenesis rate (+ 3.2 W/kg) ensures the maintenance of homeothermy in cold water as in the air. Similarly in the king penguin chicks, the metabolic rate, measured during repeated immersions in cold water (7 degree C), increased from 6 to 10 W/kg.

  109. Biomass of birds and mammals in the Ross Sea

    D. G. Ainley.

    SCAR Symposium on Antarctic Biology, Wilderness (South Africa), 12-16 Sep 1985

    The distribution and biomass of birds and mammals were determined for the Ross Sea, Antarctica. Within the boundaries of the Ross Sea, the biomass of birds, seals and whales was estimated to be 0.044-0.070, 0.068-0.089 and 0.182-0.394 g m super(-2), respectively. The bird community was dominated in abundance by Antarctic Petresl, Thalassoica antarctica , and in biomass by penguins. The mammal community was dominted in abundance by Crabeater Seals, Lobodon carcinophagus , and in biomass by crabeater Seals and Minke Whales, Balaenoptera acutorstrata .

  110. Interaction between antarctic and sub-antarctic marine, freshwater and terrestrial organisms

    J. C. Hureau.

    SCAR Symposium on Antarctic Biology, Wilderness (South Africa), 12-16 Sep 1985

    Certain recent studies have shown that the terrestrial micro-flora play an important role in Antarctica as well as in the Sub-Antarctic islands, due to a substantial influx of run-off water. Similarly, the terrestrial micro-fauna is linked with the coastal marine micro-fauna; coastal birds, such as terms and penguins, and seals, such as the Elephant seal, Mirounga leonina , playing important roles in coastal ecosystems. It is necessary to emphasize the role played by seabirds which introduce significant quantities of nutrients into terrestrial ecosystems: it has been demonstrated that in one Sub-Antarctic island this amounts to about 56 kg hau-1yru-1of N alone. The role of seals which breed on land and feed at sea is also important, because they constitue a link between terrestrial micro-organisms and marine fauna.

  111. Skua predation on penguin eggs: The influence of egg quality and location

    Mde L. Brooke.

    Wilson Bulletin, Vol. 97, No. 3, 1985, pp. 366-368.

    The two experiments reported here demonstrate that skuas take eggs placed within nests more rapidly than eggs placed on the ground, and that intact eggs are taken more rapidly than broken eggs. The skuas' ability to use the cues of prey condition and location ensures that they usually concentrate their search on the most profitable eggs, namely those within the colony. But broken eggs also were occasionally taken. This may be the result of errors in recognition, or it may be an instance of the sampling behavior that enables skuas to discover and then exploit new sources of food.

  112. The behavior of penguins: Adapted to ice and tropics

    D. Mueller-Schwarze.

    ALBANY, NY: STATE UNIVERSITY OF NEW YORK PRESS, 1984

    This book is a general account of the behavior and life history of penguins. In the first section, the history, zoogeography, social behavior, diving, and adaptations of the family are briefly covered. The second part of the book focuses on the species of penguins and their breeding, behavior, diets, predators and migrations. The Adelie penguin (Pygoscelis adeliae ) is discussed in the most detail. The book is illustrated with numerous photographs of penguins and their environment.

  113. Energetics of walking in penguins

    Y. Le Maho and G. Dewasmes.

    American Physiology Society, Comparative Physiology Section, Symposium on Seabird Energetics, Honolulu, HI (USA), 23-24 Aug 1983

    The cost of walking must be considered as an important proportion of the energy budget of penguins because for most species the breeding colonies are not close to the sea. The distances some species have to walk before reaching their colonies may be considerable. For example there are often hundreds of km between Emperor Penguin (Aptenodytes forsteri ) colonies – which are established on well-anchored sea-ice along the coasts of the antarctic continent – and the open sea. Adelie penguins (Pygoscelis adeliae ) may also have to walk more than 100 km from the sea to their colonies.

  114. Energy cost of incubation to the parent seabird

    G. S. Grant.

    American Physiology Society, Comparative Physiology Section, Symposium on Seabird Energetics, Honolulu, HI (USA), 23-24 Aug 1983

    In this chapter, the author introduces and briefly discusses the methods (and results obtained) used to measure, calculate, or estimate incubating and resting metabolic rates of petrels, penguins, terns, and other birds.

  115. The Humboldt penguin in Peru

    C. Hays.

    Oryx, Vol. 18, No. 2, 1984, pp. 92-95.

    Numbers of Humboldt penguins Spheniscus humboldti , which live on the coast and islands of Chile and Peru, have been declining since the mid-1800s. Extracting guano for fertiliser has damaged their breeding sites; they have been exploited for food and skins and captured for pets or zoos; they are incidentally caught in fishing nets and recent overfishing may have caused a food shortage. The author surveyed the Humboldt penguins in Peru in 1981 and here discusses the conservation measures that are being taken.

  116. The biology of well-dressed birds

    JE McCosker.

    Pacific Discovery, 1983.

    There are seventeen living species of penguins, but only two are restricted to polar ice. Most species favor somewhat warmer environments, and one species inhabits the equatorial Galapagos Islands. The obscure origin of penguins, as well as the derivation of their name, is fair game for scientific detectives. The earliest penguin fossils are 70 to 100 million years old, and they suggest that penguins share a common ancestor with the living tube-nosed birds, which include the petrels, shearwaters, and albatrosses.

  117. Fossil seabirds and changing marine environments in the Late Tertiary of South Africa

    S. L. Olson.

    South African Journal of Science, Vol. 79, No. 10, 1983, pp. 399-402.

    Fossil seabirds from Early Pliocene (5 Myr ago) deposits in the southwestern Cape Province indicate there was a colder, more sub-Antarctic marine environment in this region in the Late Tertiary than at present, thus corroborating and forcibly augmenting similar evidence from molluscs and pinnipeds. The Pliocene seabird fauna included at least four species of penguins (Spheniscidae), an albatross (Diomedeidae), two storm-petrels (Oceanitidae), three species of prions (Pachyptila ), several shearwaters (Puffinus and relatives), a diving petrel (Pelecanoides), a booby ( Sula and at least two species of cormorants (Phalacrocoracidae). Gulls and terns (Laridae) were present but it cannot be determined if any of these were truly marine species. With the possible exception of the cormorants and larids, all of the elements of the Early Pliocene marine avifauna have either become extinct or have retreated from the Cape region.

  118. Egg composition and hatchling precocity in seabirds

    A. J. Williams, W. R. Siegfried and J. Cooper.

    Ibis, Vol. 124, No. 4, 1982, pp. 456-470.

    This paper presents analyses of the composition (shell, yolk, albumen) and of the quality (lipid, protein and water contents) of yolk and albumen of eggs of 25 species of seabirds belonging to the Sphenisciformes, Procellariiformes, Pelecaniformes, and Lari of the Charadriiformes. These data are compared with those published for species in the same orders and suborders, and the combined seabird data are compared with published data for non-seabirds. Variation in the proportionate weight of eggshell is not related to hatchling precocity but is probably due to adaptive differences in nest substraturm and the agility of the incubating birds. Lipid and protein contents of yolk, and water content of albumen, are uniform in eggs of all examined species. Protein levels of albumen and water content of yolk and of entire egg contents vary greatly between taxa.

  119. (Aerial surveys of antarctic aquatic mammals and birds in the South Shetland Islands, Chile.)

    D. Torres N, J. Yanez V, M. Gajardo G and M. Sallaberry A.

    Boletin antartico chileno.Santiago, Vol. 1, No. 2, 1981, pp. 6-10.

    Aerial surveys over the South Shetland Islands indicate that the population of 5 pinniped species has decreased in number. Some 28 colonies of penguins were also observed but their identification at species level was not possible.

  120. Food of Chinstrap penguins Pygoscelis antarctica and Macaroni penguins Eudyptes chrysolophus at Elephant Island group, South Shetland Islands

    J. P. Croxall and J. R. Furse.

    Ibis, Vol. 122, No. 2, 1980, pp. 237-245.

    Food samples were obtained from 4 colonies on 3 islands: Chinstrap Cove (10,700 pairs of Chinstrap, 700 pairs of Macaroni) and Cape Bowles (91,000 Chinstrap) on Clarence Is.; near the Spit (6,000 pairs Chinstrap, 500 pairs Macaroni) on Gibbs Is.; at Camp Corrie (8,800 pairs Chinstrap) on O'Brien Is. Sampling was timed in relation to breeding season events. The main features of the diets are that Chinstrap penguins appear to take large Euphausia superba almost exclusively whereas krill, fish and Thyssanoessa are equally important to Macaroni. The overall mean weights of stomach contents of the two species are not significantly different although the female Macaroni birds collected differ significantly in weight from male, but not female Chinstrap. The 2 groups of Macaroni samples differ in that those from Gibbs Is. contain all the fish and small E. superba recorded, but only 2% by weight of the large E. superba and 17% by weight of Thyssanoessa .

  121. The food of Gentoo penguins Pygoscelis papua and Macaroni penguins Eudyptes chrysolophus at South Georgia

    J. P. Croxall and P. A. Prince.

    Ibis, Vol. 122, No. 2, 1980, pp. 245-253.

    Forty samples of stomach contents were taken in groups of 10 at weekly intervals from adults of each species on Bird I. The collection of samples was gauged so as to enumerate adequately the respective diets during the period of chick feeding. There were no significant differences in sample weight or adult weight between the groups of samples for either species. As the season progressed the Gentoo sample groups showed a small decrease in krill content together with a significant increase in fish content (between 20th Jan and 4th Feb). The Macaroni samples showed an increase from 70 to 90% by weight of large krill with a decrease in small krill from 30% to 5% between 31st Jan and 7th Feb. The main differences between the 2 species at Bird Is. were that the Gentoo penguins take a substantial amount of fish and only prey on large E. superba whereas Macaroni penguins take a negligible amount of fish and a significant amount of small E. superba . However, although both take large E. superba during the breeding season, competition may be reduced due to the fact that Macaroni forage over much greater distances than do Gentoo.

  122. Foraging ranges of krill-eating penguins

    A. J. Williams and W. R. Siegfried.

    Polar Rec., Vol. 20, No. 125, 1980, pp. 156-162.

    In order for studies on the breeding success of penguins to be meaningful, areas of ocean around the breeding sites being monitored, should be declared control zones within which commercial fishing for krill (Euphausia superba ) should be prohibited; krill being the main food of these penguins. This paper reviews the currently available information on foraging ranges of krill-eating penguins. Estimates of these foraging ranges are crude, being derived from the duration of absence from the breeding site and very rough estimates of speed of paddling or swimming and depth of diving etc. Until radiotelemetry and other modern techniques are perfected to study penguins at sea, little improvement can be made on these crude estimates of breeding birds' foraging ranges. Thus at the present time it would be prudent to control commercial krill fishing in areas within a 20-km radius of penguin breeding colonies being monitored during the BIOMASS survey.

  123. Mortality in little penguins (Eudyptula minor ) along the coast of Victoria, Australia

    D. L. Obendorf and K. McColl.

    J. Wildl. Dis., Vol. 16, No. 2, 1980, pp. 251-259.

    Forty-eight E. minor consisting of 21 (43.7%) mature, 18 (37.5%) juvenile and 9 (18.7%) of undetermined age, from 10 Victorian coastal localities were exained during 1977-78. Thirty-seven (77%) of all penguins were in poor body condition with moderate to heavy burdens of internal and external parasites. Acute parasitic gastric ulceration with accompanying hemorrhage, was implicated in the death of four birds. Chronic gastric ulcers were thought to have caused appetite depression and starvation in 28 birds. Other significant lesions encountered included renal coccidiosis, parasitic cholangiohepatitis and pulmonary aspergillosis. It is suggested that the increased mrtality experienced during 1977-78 was due to starvation or to exacerbation of the effects of existing parasite burdens on starving and exhausted birds.

  124. Offspring reduction in macaroni and rockhopper penguins

    A. J. Williams.

    Auk, Vol. 97, No. 4, 1980, pp. 754-759.

    Mortality of macaroni penguin (Eudyptes chrysolophus ) and rockhopper penguin [E. chrysocome (crestatus )] eggs and chicks was investigated at Marion Island. Two eggs wre laid at each nest, but no pair reared more than one chick. Egg mortality exceeded chick mortality in both species. Both eggs hatched at 6% of rockhopper penguin nests and at no macaroni penguin nests. When both eggs hatched, one chick died of starvation within 12 days. Chicks were successfully reard from 43% and 34% of all eggs laid by macaroni and rockhopper penguins, respectively. Egg mortality was greater and occurred earlier, and chick mortality was lower, in macaroni than in rockhopper penguins. Offspring reduction was closely related to egg dimorphism and differential egg mortality. In both species the first laid (A) egg was markedly lighter than the second (B) egg. Mortality of A-eggs was 99.7 and 88% and of B-eggs 44 and 32% in macaroni and rockhopper penguins, respectively. Chicks were raised successfully from 3% of all A-eggs laid by rockhopper penguins. No A-egg chicks were reared by macaroni penguins. The B-eggs, a better investment, were treated preferentially, and the smaller A-eggs were often disregarded. The A-egg functions as an insurance against the loss or failure to hatch of the B-egg in most rockhopper penguin clutches but serves no obvious function in the majority of macaroni penguin clutches.

  125. Survival and mortality in a population of Adelie penguins

    D. G. Ainley and D. G. DeMaster.

    Ecology, Vol. 61, No. 3, 1980, pp. 522-530.

    Life table and survivorship estimates were calculated for Pygoscelis adeliae of known age, sex, and breeding status, from banded and web-punched fledglings at Cape Crozier, Ross Island. Survivorship estimates were also calculated for the yellow-eyed penguin (Megadyptes antipodes) using published data. Results indicate that breeding is risky, especially in the Adelie penguin and particularly among younger breeders. In both species, females breed at younger ages than males and in any mature age class a greater proportion of females than males breed. These factors result in higher mortality among females and a sex ratio that changes to favor males in the older age groups. The oldest individuals tend to be those that are habitually inept breeders or non-breeders. The higher annual mortality and shorter life-span in the Adelie Penguin compared to the yellow-eyed penguin are probably due in part to heavier predation pressure.

  126. Nest-site competition between Adelie and chinstrap penguins: an ecological interpretation

    W. Trivelpiece and N. J. Volkman.

    Auk, Vol. 96, No. 4, 1979, pp. 675-681.

    A study of nest-site competition between Adelie (Pygoscelis adeliae ) and chinstrap (P. antarctica ) penguins was conducted during the 1977-78 austral summer at Point Thomas, King George Is., Antarctica. Data were collected on the timing of the reproductive cycle, the reproductive success, and the behavioral interactions between Adelie and chinstrap penguins in areas of competition. Adelie penguins in mixed sites had their nests usurped by arriving chinstrap males, and reproductive success was significantly depressed for Adelie pairs nesting in these areas. It is suggested that nest-site competition is a relatively recent phenomenon correlated with dramatic population increases among pygoscelids in response to the increased availability of krill in areas of past whaling activities.

  127. Jackass penguins, eggs and guano; diminishing resources at Dassen Island

    W. R. Siegfried and R. J. M. Crawford.

    S. Afr. J. Sci., Vol. 74, No. 10, 1978, pp. 389-390.

    Approximately 40% of jackass penguins, Spheniscus demersus , occur on Dassen Island (33 25' S, 18 05' E). Exploitation of the resource involves collection of eggs between Mar and June and scraping of guano in April or May. Analysis of annual guano and penguin egg harvests shows a good fit between egg and guano yields and provides evidence for a real decrease in size of the penguin population of Dassen Island.

  128. Optical performance of the penguin eye in air and water

    J. G. Sivak and M. Millodot.

    J. Comp. Physiol, Vol. 119, No. 3, 1977, pp. 241-247.

    Refractive states of 3 species of penguins, (Eudyptes cristatus, Pygoscelis papua and Aptenodytes forsteri) were measured in air and water. Little or no refractive error, with a trend toward slight myopia (less than two dioptres) was found in air in each case. Moderate hyperopia (8-13 dioptres) exists in water. The refractive findings of this study are similar to those of a preliminary study made with the Blackfoot penguin. The relatively small alteration of refractive state associated with the change from air to water (in contrast to an approximate change of 40 dioptres for the human eye) is attributed to the flattened shape of the cornea. The chromatic aberration measured in these species is insufficient to account for the hyperopia found underwater. The maximum reduction of hyperopia resulting from a monochromatic (blue, blue-green) aquatic habitat would only amount to two dioptres. It is speculated that the remaining hyperopia is nullified by an accommodative mechanism.