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Steven D Emslie - One of the best experts on this subject based on the ideXlab platform.
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intraspecific variation in mercury δ15n and δ13c among 3 adelie penguin Pygoscelis adeliae populations in the northern antarctic peninsula region
Environmental Toxicology and Chemistry, 2021Co-Authors: Ashley Mckenzie, Anahi M Silvestro, Lucas J Marti, Steven D EmslieAbstract:Mercury (Hg) is a pervasive environmental contaminant that accumulates in the organs and tissues of seabirds at concentrations capable of causing acute or long-term adverse health effects. In the present study, Hg concentrations in Adelie penguin (Pygoscelis adeliae) egg membranes and chick feathers served as a proxy for Hg bioavailability in the marine environment surrounding the northern Antarctic Peninsula. Stable isotopes were measured in conjunction with Hg to infer information regarding feeding habits (δ15 N, diet/trophic level; δ13 C, foraging habitat). The Hg concentrations were low relative to toxicity benchmark values associated with adverse health effects in birds and ranged between 0.006 and 0.080 µg g-1 dry weight (n = 65) in egg membranes and 0.140 to 1.05 µg g-1 fresh weight (n = 38) in feathers. Egg membrane δ15 N signatures suggested that females from different breeding colonies had similar diets consisting of lower and higher trophic prey prior to arrival to breeding grounds. In contrast, δ15 N signatures in feathers indicated that chick diet varied by colony. The Hg concentrations demonstrated significant positive relationships with δ15 N, providing support for the hypothesis of Hg biomagnification up the food chain. The δ13 C signatures in both tissue types provided evidence of foraging habitat segregation among populations. The differences in Hg exposure and foraging ecology suggest that each colony has localized foraging behaviors by breeding adults that warrant additional investigation. Environ Toxicol Chem 2021;40:2791-2801. © 2021 SETAC.
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intraspecific variation in mercury δ 15 n and δ 13 c among three adelie penguin Pygoscelis adeliae populations in the northern antarctic peninsula region
Environmental Toxicology and Chemistry, 2021Co-Authors: Ashley Mckenzie, Anahi M Silvestro, Lucas J Marti, Steven D EmslieAbstract:Mercury (Hg) is a pervasive environmental contaminant that accumulates in the organs and tissues of seabirds at concentrations capable of causing acute or long-term adverse health effects. In the present study, Hg concentrations in Adelie penguin (Pygoscelis adeliae) egg membranes and chick feathers served as a proxy for Hg bioavailability in the marine environment surrounding the northern Antarctic Peninsula. Stable isotopes were measured in conjunction with Hg to infer information regarding feeding habits (δ15 N, diet/trophic level; δ13 C, foraging habitat). The Hg concentrations were low relative to toxicity benchmark values associated with adverse health effects in birds and ranged between 0.006 and 0.080 µg g-1 dry weight (n = 65) in egg membranes and 0.140 to 1.05 µg g-1 fresh weight (n = 38) in feathers. Egg membrane δ15 N signatures suggested that females from different breeding colonies had similar diets consisting of lower and higher trophic prey prior to arrival to breeding grounds. In contrast, δ15 N signatures in feathers indicated that chick diet varied by colony. The Hg concentrations demonstrated significant positive relationships with δ15 N, providing support for the hypothesis of Hg biomagnification up the food chain. The δ13 C signatures in both tissue types provided evidence of foraging habitat segregation among populations. The differences in Hg exposure and foraging ecology suggest that each colony has localized foraging behaviors by breeding adults that warrant additional investigation. Environ Toxicol Chem 2021;00:1-12. © 2021 SETAC.
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stable isotope analyses of ancient and modern adelie penguin Pygoscelis adeliae mummies from the ross sea region antarctica
Polar Biology, 2019Co-Authors: Allyson K Kristan, Steven D Emslie, William P PattersonAbstract:We performed stable carbon (δ13C) and nitrogen (δ15N) isotope analyses of 12 ancient Adelie penguin (Pygoscelis adeliae) chick mummies recovered from abandoned colonies in the Ross Sea region, Antarctica, to investigate isotopic variation and fractionation over time. We also examined latitudinal variation in penguin diet to address if the modern dietary pattern (an increase in krill as dominant prey to the north) in this region has existed in the past or if this is a recent phenomenon. The ancient mummies range in age from > 48,000 14C years before present (BP) to ~ 500 calendar years BP. Feather, skin, bone, and toenail samples were analyzed from each individual where available. Identical analyses were performed on five modern mummified Adelie penguin chick carcasses and breast feathers of ten recently dead chicks from each of two active colonies, Cape Hallett and Adelie Cove. We found significantly lower δ15N values in Cape Hallett modern chicks as compared to those from Adelie Cove, indicating an entire trophic-level difference in modern diet that agrees with other studies in this region. The ancient mummies exhibited consistent isotopic fractionation of δ13C among the four different tissues through time. Variation in δ15N and δ13C values was greater in bone and skin than in feather or toenail, but δ15N in all four tissues indicated similar dietary trends with latitude as occurs in this region today. These results provide insight into the dietary variability of Adelie penguins across the Ross Sea region and a framework for similar analyses with other avian species.
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recent occupation by adelie penguins Pygoscelis adeliae at hope bay and seymour island and the northern enigma in the antarctic peninsula
Polar Biology, 2018Co-Authors: Steven D Emslie, Ashley Mckenzie, Lucas J Marti, Mercedes SantosAbstract:We excavated active and abandoned Adelie Penguin (Pygoscelis adeliae) colonies at Seymour Island and Hope Bay, Antarctic Peninsula, to determine an occupation history for this species at these sites. Previous research at Hope Bay has indicated an occupation there since the middle Holocene, based on a sediment record from Lake Boeckella. Excavations revealed only shallow and relatively fresh ornithogenic soils in the active colonies at the two localities. At least 53 abandoned pebble mounds were located at Hope Bay of which nine were excavated and four were sampled by probing to recover organic remains to determine their age. Radiocarbon dating of egg membrane, feather, and bone from both sites revealed a young occupation dating to less than ~600 years after correcting for the marine carbon reservoir effect. The mismatch in the geologic record of Adelie Penguin occupation in the northern Antarctic Peninsula, including Lake Boeckella sediments and geologic deposits and lake sediments on King George Island, with more direct evidence of breeding colonies from ornithogenic soils from active and abandoned colonies is hereby referred to as the ‘northern enigma’ as it does not occur in other regions of Antarctica including the southern Antarctic Peninsula, East Antarctica, or the Ross Sea, where the penguin record extends to the early to middle Holocene and matches well with the geologic record of deglaciation and penguin occupation. As yet, there is no convincing explanation for the ‘northern enigma’.
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high mitogenomic evolutionary rates and time dependency
Trends in Genetics, 2009Co-Authors: Steven D Emslie, Sankar Subramanian, Dee R Denver, Craig D Millar, Tim H Heupink, Angelique Aschrafi, Carlo BaroniAbstract:Using entire modern and ancient mitochondrial genomes of Adelie penguins (Pygoscelis adeliae) that are up to 44000 years old, we show that the rates of evolution of the mitochondrial genome are two to six times greater than those estimated from phylogenetic comparisons. Although the rate of evolution at constrained sites, including nonsynonymous positions and RNAs, varies more than twofold with time (between shallow and deep nodes), the rate of evolution at synonymous sites remains the same. The time-independent neutral evolutionary rates reported here would be useful for the study of recent evolutionary events.
John F Cockrem - One of the best experts on this subject based on the ideXlab platform.
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corticosterone responses in birds individual variation and repeatability in adelie penguins Pygoscelis adeliae and other species and the use of power analysis to determine sample sizes
General and Comparative Endocrinology, 2009Co-Authors: John F Cockrem, Paul D Barrett, Jane E Candy, Murray A PotterAbstract:Plasma corticosterone concentrations increase when birds experience a stressor, and in this study we quantified variation in corticosterone responses for the first time in a species of free-living bird. Adelie penguins (Pygoscelis adeliae) nesting at Cape Bird on Ross Island in Antarctica were sampled on three occasions. Penguins with relatively low or high corticosterone responses on the first occasion had consistently low or high responses, as previously found for great tits and chickens. A model for birds is proposed in which birds with low corticosterone responses and proactive personalities are likely to be more successful (have greater fitness) in constant or predictable conditions, whilst birds with reactive personalities and high corticosterone responses will be more successful in changing or unpredictable conditions. There is thus no linear relationship between the size of a corticosterone response and fitness. Whilst the absolute magnitude of corticosterone responses varies markedly across species of birds, coefficients of variation are similar. Individual corticosterone responses are generally repeatable, with significant statistical repeatabilities for 30 min corticosterone concentrations and integrated corticosterone concentrations in the Adelie penguin, great tit and chicken. Coefficients of variation in corticosterone responses between birds and power analyses were used to provide a rule of thumb for determining differences between groups of birds in mean corticosterone concentrations to enable statistical analyses to have acceptable levels of statistical power for given sample sizes. It is suggested that power analyses and this rule of thumb be adopted in future investigations of corticosterone responses in birds.
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corticosterone in relation to body mass in adelie penguins Pygoscelis adeliae affected by unusual sea ice conditions at ross island antarctica
General and Comparative Endocrinology, 2006Co-Authors: John F Cockrem, Murray A Potter, E J CandyAbstract:Penguins naturally fast each year during breeding and again whilst moulting, and may lose more than 40% of body mass during a fast. Fasting in emperor (Aptenodytes forsteri) and king (Aptenodytes patagonicus) penguins has been divided into three phases, with phase III characterised by an increased rate of body mass loss, increased plasma corticosterone concentrations, and a change in behaviour leading to abandonment of the breeding attempt and return to sea to feed. Initial corticosterone concentrations and corticosterone responses to a handling stressor were measured in the current study to determine if they increase during phase III of fasting in Adelie penguins (Pygoscelis adeliae). The study was conducted in 2001 at the northern Cape Bird colony on Ross Island, Antarctica. Penguin breeding on Ross Island was disrupted in the 2001-2002 summer by a large iceberg (B15A) which stopped the normal movement of sea ice in the Ross Sea. Penguins departing from the Cape Bird colony were lighter than returning or incubating birds (3.39+/-0.10cf. 4.16+/-0.06 and 4.07+/-0.08kg). It is likely that the departing birds were males that had been lighter than normal when they arrived at the colony. Initial plasma corticosterone concentrations were higher in departing than returning or incubating penguins (6.89+/-1.69cf. 2.36+/-0.42 and 1.08+/-0.19ng/ml). Corticosterone responses to handling were also greater in departing penguins. Initial plasma corticosterone, concentrations at 30min and total and corrected integrated corticosterone responses were inversely related to body mass in departing penguins, whereas there were no relationships in arriving penguins. beta-hydroxybutyrate and uric acid concentrations were consistent with departing birds having entered phase III of fasting. The results indicate that corticosterone and corticosterone responses are elevated in phase III of fasting in the Adelie penguin.
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circadian rhythms of plasma melatonin in the adelie penguin Pygoscelis adeliae in constant dim light and artificial photoperiods
Journal of Pineal Research, 1991Co-Authors: John F CockremAbstract:The response of plasma melatonin in Adelie penguins (Pygoscelis adeliae) to constant dim light and to light/dark cycles was measured to determine the capacity of the pineal gland to secrete melatonin after exposure to continuous daylight for 2 months. Penguins were moved in mid-summer from the natural photoperiod to either constant dim light (n = 10), to a 12L:12D light/dark cycle (n = 5), or to a 12L:12D light/dark cycle with a 30 min light pulse (50-155 lux) on the third (n = 4) or sixth (n = 5) "night." Blood samples were collected regularly through cannulae for up to 33 h. The birds in dim light were sampled after 2 days, with samples obtained over at least 24 h from 7 birds. Three of these birds had melatonin rhythms (peak levels 66.7-130.2 pg/ml) whereas the other 4 birds had constant low levels (less than 44 pg/ml). The phase of the rhythm was similar for all 3 birds. This is consistent with the pacemaker that regulates the circadian rhythm of melatonin secretion being entrained to a period of 24 h when the penguins were exposed to the natural photoperiod. Mean melatonin levels (42.7 +/- 2.5 pg/ml) were elevated compared to those previously reported in penguins under natural daylight. All penguins held under a 12L:12D light/dark cycle had melatonin rhythms. The phase and form of these rhythms were similar to those reported for other birds, and they appeared to be circadian rhythms entrained by the light/dark cycle.(ABSTRACT TRUNCATED AT 250 WORDS)
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plasma melatonin in the adelie penguin Pygoscelis adeliae under continuous daylight in antarctica
Journal of Pineal Research, 1991Co-Authors: John F CockremAbstract:Circadian rhythms of melatonin secretion in birds are influenced by daylength and light intensity. Daily patterns of melatonin secretion were examined in Adelie penguins (Pygoscelis adeliae) under natural continuous daylight at Cape Bird, Antarctica (77 degrees S). Although daylight is continuous during the Antarctic summer there was a marked daily cycle of light intensity. However, there was no relationship between mean plasma melatonin levels and time of day in groups of 2-10 penguins sampled at 2-3 h intervals in November, December, or January. Mean melatonin levels over 24 h in groups of birds from which single samples were collected, or in groups of birds sampled repeatedly through cannulae, were low (12.4 +/- 1.2 pg/ml-28.8 +/- 4.4 pg/ml for 4 sampling periods; n = 22-163). Levels in individual birds were, however, quite variable and ranged from 5.0-68.1 pg/ml. Some birds had periods of increased melatonin levels that tended to occur during the time of day when light intensity was least. One bird had a clear low amplitude melatonin rhythm with a peak during the time of least light intensity. These results, the first for any bird under a natural photoperiod, indicate that melatonin secretion is inhibited by natural continuous daylight, but that it is not abolished.
Katsufumi Sato - One of the best experts on this subject based on the ideXlab platform.
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individual variation of foraging behavior and food provisioning in adelie penguins Pygoscelis adeliae in a fast sea ice area
The Auk, 2010Co-Authors: Yutaka Watanuki, Akinori Takahashi, Katsufumi SatoAbstract:ABSTRACT. To understand the effects of foraging behavior on the amount of food provided to chicks (meal mass and frequency), we monitored nest attendance and diving behavior of 20 Adelie Penguin (Pygoscelis adeliae) pairs that were rearing chicks. Because ice forms on the sea surface at night, parents foraged through cracks or within leads in the sea ice mainly during 0800–2400 hours. Birds that departed the colony in the afternoon and returned in the evening of the same day fed their chicks more frequently than those that made longer trips (i.e., those that departed in the afternoon and returned the next day or departed in the early morning and returned that evening). When the duration of the longest dive bout during each trip was longer, parents brought back heavier meals that contained larger krill. On average, birds made longer dive bouts when diving to greater depths. Thus, daily foraging pattern and foraging depth affected the provisioning rate, but the proportion of time spent foraging during the p...
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feeding area specialization of chick rearing adelie penguins Pygoscelis adeliae in a fast sea ice area
Ibis, 2003Co-Authors: Yutaka Watanuki, Akinori Takahashi, Katsufumi SatoAbstract:Individual feeding area specialization has been reported for several seabird species. Researchers suspect that this behaviour results in feeding and/or reproductive advantages. Adelie Penguins Pygoscelis adeliae feed in small predictable open waters in a fast sea-ice area near Syowa Station, Antarctica. Their feeding sites were determined by radiotracking both members of 20 pairs rearing chicks. Twenty-five birds repeatedly fed in distinct areas more frequently than expected by chance, while the remaining 15 birds had no significant feeding area specialization. Birds seemed to feed at sites that were closer to their most recent feeding sites than they were to earlier feeding sites. Variation in specialized area, degree of feeding area fidelity and distance to feeding sites had no significant effect on the number of feeds that a bird brought to chicks per day. Neither did the estimated mass of feeds brought per day per pair depend on feeding area specialization.
Boris M Culik - One of the best experts on this subject based on the ideXlab platform.
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diving heart rates in adelie penguins Pygoscelis adeliae
Comparative Biochemistry and Physiology Part A: Physiology, 1992Co-Authors: Boris M CulikAbstract:Abstract 1. l. In Antarctica, two Adelie penguins were implanted with heart rate (HR) transmitters and released in their breeding colony where they resumed incubation. 2. 2. HR while at rest and lying in the colony were 67 and 77 beats per min (bpm), respectively. 3. 3. For diving experiments, the birds were introduced into a still-water canal, 21 m long, with one respiration chamber at each end. 4. 4. The birds swam underwater for 49 and 76% of the time at speeds of 1.5 and 2.5 m/sec, respectively. 5. 5. When floating quietly at the surface, HR in the first penguin was 89 bpm. 6. 6. Pre-dive HR varied with duration of the inter-dive interval, being highest (250 bpm) when the bird dived in rapid succession (surface times 7. 7. Mean HR while diving was constant (107 bpm) and did not vary either with surface time, or with time submerged (0–15 sec). 8. 8. Pre-dive HR and diving HR were not correlated, 9. 9. The extent of bradycardia upon immersion was dependent upon surface time. 10. 10. There was a good correlation between HR and oxygen consumption in both birds, suggesting that HR might be used to determine energy expenditure.
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people in antarctica how much do adelie penguins Pygoscelis adeliae care
Polar Biology, 1991Co-Authors: Rory P Wilson, Boris M Culik, R Danfeld, Dieter AdelungAbstract:In the course of physiological field studies, we opportunistically examined the effects of humans and aircraft on breeding Adelie Penguins Pygoscelis adeliae. Proximity to both aircraft and humans caused substantial increases in penguin heart rate even when no external stress was manifest. A solitary human at 20 m distance from commuting penguins on a well-used pathway caused the birds to deviate by 70 m. Birds at nests exposed to a single human fled much more readily when the brood consisted of large chicks (critical distance 6.1 m) rather than small chicks (critical distance 1.3 m) or eggs (critical distance 0.3 m). Aircraft caused birds to panic at distances greater than 1,000 m and 3 days exposure to a helicopter inhibited birds that had been foraging from returning to their nests, caused bird numbers in the colonies to decrease by 15% and produced an active nest mortality of 8%. Based on this data, we make recommendations to minimize stress on Adelie Penguin colonies exposed to man.
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energetics of under water swimming in adelie penguins Pygoscelis adeliae
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 1991Co-Authors: Boris M Culik, Rory P WilsonAbstract:The energy consumption of Adelie penguins while at rest in water (8.4 W·kg-1 at 4°C) or swimming below the surface was determined using a 21 m long canal fitted with respiration chambers at each end. Penguins chose to swim 86% of the time at speeds recorded in nature. Cost of transport was lowest (7.9 J·kg-1·m-1) at 1.7–2.3 m·s-1, corresponding to a power input of 15.8 W·kg-1, and only 50% as high as previously reported. Assuming a muscle efficiency of 0.25, propulsion efficiency is 0.4 and overall efficiency is 0.1. Calculated food requirements vary between 1060 g krill per adult and foraging trip at the beginning of the breeding season and 2500 g at the period of highest demand, prior to creching of the chicks.
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swimming energetics and performance of instrumented adelie penguins Pygoscelis adeliae
The Journal of Experimental Biology, 1991Co-Authors: Boris M Culik, Rory P WilsonAbstract:The effects of implanted and of externally attached instruments (1.8% of body cross-sectional area) were studied on Ade1ie penguins ( Pygoscelis adeliae ) using a 21 m long canal in conjunction with respirometry at Esperanza Bay, Antarctica. Penguins in both groups covered the same mean distance (173 m in 5 min) as controls. Implanted birds preferred to swim at slower speeds (1.3-1.7 ms −1 ) than did the controls (1.9-2.1 ms −1 ), whereas penguins with external instruments had a bimodal speed distribution with maxima at 1.7-1.9 and 2.3-2.5 ms −1 . Power input during swimming averaged 20% less in implanted penguins (12.7 W kg −1 ) and 42% more in penguins fitted with external instruments (22.5 W kg −1 ) compared with controls (15.8 W kg −1 ). Similarly, cost of transport was 23% lower in implanted penguins (7.0 J kg −1 m −1 ) and 25% higher in externally instrumented birds (11.3 J kg −1 m −1 ) compared with controls (9.0 J kg −1 m −1 ). Possible reasons for the effects caused by the devices are discussed and the advantages and disadvantages of implanted and externally fitted devices are compared.
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depth utilisation by breeding adelie penguins Pygoscelis adeliae at esperanza bay antarctica
Marine Biology, 1991Co-Authors: Rory P Wilson, H J Spairani, Dieter Adelung, Boris M Culik, Nestor CoriaAbstract:Miniature depth gauges were attached in December 1987 and January 1988 to Adelie penguins,Pygoscelis adeliae, breeding at Esperanza on the Antarctic Peninsula. Results from 34 birds showed that foraging penguins with eggs and with brooded and creching chicks spent mean periods away from the nest of 96, 36 and 21 h, respectively, during which time means of 29.0 h (30%), 11.2 h (31%) and 2.7 h (13%), respectively, were spent under water at depths > 5 m. Time under water was positively correlated with time absent from nest. Maximum depth reached was 170 m but overall birds spent most time at shallower depths. Birds foraging for brooded chicks dived deeper than birds foraging for creching chicks. Stomach-pumping indicated that the principal prey caught at this time was krill,Euphausia superba. Mean mass changes of adults during single foraging trips indicated that krill were caught at a mean rate of 7.2 g min−1 spent under water.
David G Ainley - One of the best experts on this subject based on the ideXlab platform.
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multi year serological evaluation of three viral agents in the adelie penguin Pygoscelis adeliae on ross island antarctica
Polar Biology, 2018Co-Authors: Wray W Grimaldi, David G Ainley, Melanie MassaroAbstract:Serological assays are commonly used in wildlife health studies to screen for exposure of an individual or a population to infectious agents. Such assays can therefore provide useful information regarding the health status of an individual or for determining the prevalence of a pathogen within a population. In this study, serological assays of three viral agents have been conducted on the Adelie Penguin (Pygoscelis adeliae) on Ross Island, Ross Sea, Antarctica. We sampled adult Adelie Penguins during three consecutive summer breeding seasons (2010–2011, 2011–2012 and 2012–2013), and tested those samples for antibodies to avian influenza A virus, Newcastle disease virus, and infectious bursal disease virus. No antibodies were detected for avian influenza A virus in any season. Two samples in 2012–2013 were positive for Newcastle disease virus antibodies and a total of 10 samples were positive for infectious bursal disease virus antibodies during this study. This information establishes baseline data for these three viruses in Adelie Penguins at this location and can be used for future comparisons of disease prevalence in this population.
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sex based differences in adelie penguin Pygoscelis adeliae chick growth rates and diet
PLOS ONE, 2016Co-Authors: Scott Jennings, Grant Ballard, Katie M Dugger, Arvind Varsani, David G AinleyAbstract:Sexually size-dimorphic species must show some difference between the sexes in growth rate and/or length of growing period. Such differences in growth parameters can cause the sexes to be impacted by environmental variability in different ways, and understanding these differences allows a better understanding of patterns in productivity between individuals and populations. We investigated differences in growth rate and diet between male and female Adelie Penguin (Pygoscelis adeliae) chicks during two breeding seasons at Cape Crozier, Ross Island, Antarctica. Adelie Penguins are a slightly dimorphic species, with adult males averaging larger than adult females in mass (~11%) as well as bill (~8%) and flipper length (~3%). We measured mass and length of flipper, bill, tibiotarsus, and foot at 5-day intervals for 45 male and 40 female individually-marked chicks. Chick sex was molecularly determined from feathers. We used linear mixed effects models to estimate daily growth rate as a function of chick sex, while controlling for hatching order, brood size, year, and potential variation in breeding quality between pairs of parents. Accounting for season and hatching order, male chicks gained mass an average of 15.6 g d-1 faster than females. Similarly, growth in bill length was faster for males, and the calculated bill size difference at fledging was similar to that observed in adults. There was no evidence for sex-based differences in growth of other morphological features. Adelie diet at Ross Island is composed almost entirely of two species—one krill (Euphausia crystallorophias) and one fish (Pleuragramma antarctica), with fish having a higher caloric value. Using isotopic analyses of feather samples, we also determined that male chicks were fed a higher proportion of fish than female chicks. The related differences in provisioning and growth rates of male and female offspring provides a greater understanding of the ways in which ecological factors may impact the two sexes differently.
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testing assumptions of central place foraging theory a study of adelie penguins Pygoscelis adeliae in the ross sea
Journal of Avian Biology, 2015Co-Authors: Glenn R Ford, David G Ainley, Amelie Lescroel, Phil Ob Lyver, Viola Toniolo, Grant BallardAbstract:We investigated central place foraging (CPF) in the context of optimal foraging theory in Ad e lie penguins Pygoscelis adeliae of the southern Ross Sea by using satellite tracking and time-depth recorders to explore foraging at two spatio-temporal scales: within the day-to-day (sub-mesoscale: single foraging trip, 10s of km 2 ) and the entire breeding season (mesoscale: trips by multiple individuals across the collective foraging area, 100s of km 2 ). Specifi cally, we examine whether three basic assumptions of the Orians – Pearson CPF model, shown to occur in other CPF species, are met: 1) within a patch, the rate of prey acquisition declines with time spent in that patch; 2) food is distributed in discrete patches and is not available between those patches; and 3) CPF species have knowledge of the potential (or average, at least) feeding rate within their universe of patches, and use this knowledge to determine their foraging strategy when planning or engaging in a foraging trip. We found that prey consumption rates did not decline with time spent in patches, and penguins foraged to some degree most of the time when at sea. Food availability, as measured by foraging dive rate, appeared to be predictable within the same day at the same location, but predictability broke down after 2 d at distances 10 km away. We conclude that the assumptions of the Orians – Pearson CPF model are not a good fi t to the circumstances of Ross Sea penguins, which clearly are central place foragers.
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a novel papillomavirus in adelie penguin Pygoscelis adeliae faeces sampled at the cape crozier colony antarctica
Journal of General Virology, 2014Co-Authors: Scott Jennings, Grant Ballard, Elizabeth L Porzig, Laurel Julian, Melanie Massaro, Annie Pollard, David G AinleyAbstract:Papillomaviruses are epitheliotropic viruses that have circular dsDNA genomes encapsidated in non-enveloped virions. They have been found to infect a variety of mammals, reptiles and birds, but so far they have not been found in amphibians. Using a next-generation sequencing de novo assembly contig-informed recovery, we cloned and Sanger sequenced the complete genome of a novel papillomavirus from the faecal matter of Adelie penguins (Pygoscelis adeliae) nesting on Ross Island, Antarctica. The genome had all the usual features of a papillomavirus and an E9 ORF encoding a protein of unknown function that is found in all avian papillomaviruses to date. This novel papillomavirus genome shared ~60 % pairwise identity with the genomes of the other three known avian papillomaviruses: Fringilla coelebs papillomavirus 1 (FcPV1), Francolinus leucoscepus papillomavirus 1 (FlPV1) and Psittacus erithacus papillomavirus 1. Pairwise identity analysis and phylogenetic analysis of the major capsid protein gene clearly indicated that it represents a novel species, which we named Pygoscelis adeliae papillomavirus 1 (PaCV1). No evidence of recombination was detected in the genome of PaCV1, but we did detect a recombinant region (119 nt) in the E6 gene of FlPV1 with the recombinant region being derived from ancestral FcPV1-like sequences. Previously only paramyxoviruses, orthomyxoviruses and avian pox viruses have been genetically identified in penguins; however, the majority of penguin viral identifications have been based on serology or histology. This is the first report, to our knowledge, of a papillomavirus associated with a penguin species.
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effects of flipper bands on foraging behavior and survival of adelie penguins Pygoscelis adeliae
The Auk, 2006Co-Authors: Katie M Dugger, David G Ainley, Grant Ballard, Kerry J BartonAbstract:Abstract Since the 1950s, flipper bands have been used widely to mark penguins (Spheniscidae), but not without concerns regarding possible negative effects on survival and fitness. As part of a demographic study of Adelie Penguins (Pygoscelis adeliae) in the western Ross Sea, Antarctica, we investigated effects of flipper bands on foraging-trip duration and food loads, as well as apparent survival, during four breeding seasons (2000-2003), using mark-recapture and radio-frequency identification (RFID) technology. Foraging-trip durations were ∼8% (3.5 h) longer, on average, for banded compared with unbanded birds, but the effect varied among years. Food loads did not differ between banded and unbanded birds, but males carried heavier food loads than females. Flipper bands decreased apparent annual survival by 11–13% during 2000-2003, but over a longer time period (1996-2003) we observed high annual variability, including years of high survival for banded birds. Males had slightly higher survival than femal...
