Chinstrap Penguins Pygoscelis Antarctica Research Articles

Parasites of chinstrap penguins (Pygoscelis antarctica) from three localities in the Antarctic Peninsula and a review of their parasitic fauna

Parasites of chinstrap penguins (Pygoscelis antarctica) from three localities in the Antarctic Peninsula and a review of their parasitic fauna

Parent\u2013offspring conflict and transition to cr\xe8che phase in Chinstrap Penguins (Pygoscelis antarctica)

Parent–offspring conflict theory predicts that offspring seek to prolong the parental care period, while parents strive to shorten it as much as possible. Transition to the crèche phase in penguins involves changes in the dynamic of parental investment in chicks, and thus may be modulated by interests that benefit parent or offspring. We explored parent–offspring interactions in the Chinstrap Penguin (Pygoscelis antarctica) to understand the influence such interactions would have on transition to crèche phase. We studied the effect of hatching date, nestling age, brood size, and nest location on parent–offspring interactions and the length of the guard phase. All behavioral variables related to nestling demands for parental investment increased as well as parental aggression towards their chicks, with increased nestling age. Brood size showed significant effects on both nestling and parental behavior. Hatching date was negatively correlated with the age at crèche. Consequently, the decision to leave the chicks unguarded seemed to be more based on the condition of adults rather than of the chicks. Given the short time available for breeding in Antarctica and that penguins are long-lived birds with several opportunities to breed, there may be conflicting selective factors between investment in feeding chicks versus extending the period of resource acquisition and storage prior to moult.

Habitat preferences of Adélie Pygoscelis adeliae and Chinstrap Penguins Pygoscelis antarctica during pre-moult in the Weddell Sea (Southern Ocean)

In order to understand and mitigate for the potential impacts of anthropogenic disturbance on marine predators, it is fundamental to gain insight into the drivers behind the temporal variation in their current distribution. With this in mind, we used platform terminal transmitter devices to track Adelie Pygoscelis adeliae and Chinstrap Penguins Pygoscelis antarctica breeding on the South Orkney Islands during the pre-moult phase of their annual cycles. We show that Adelie Penguins have an affinity to forage near and moult on sea-ice, and that Chinstraps remain over the shallower shelf waters during pre-moult, and return to the colony to moult. However, habitat models developed to predict the preferred foraging habitats of penguins during pre-moult had low predictive power. This indicates that predictive models may be insufficient to understand the distribution and foraging behaviour of penguins during certain stages of the life-cycle, and that collecting empirical data from individual colonies or archipelagos is vital if we are to understand the potential implications of future climate warming, or indeed the overlap with potentially competing fisheries.

Morphological, molecular and phylogenetic analyses of the spirurid nematode Stegophorus macronectes (Johnston & Mawson, 1942).

Stegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite. Nuclear rDNA sequences (18S, 5.8S, 28S and internal transcribed spacer (ITS) regions) were isolated from S. macronectes specimens collected from the chinstrap penguin Pygoscelis antarctica Forster on Deception Island, Antarctica. Using 18S rDNA sequences, phylogenetic analyses (maximum likelihood, maximum parsimony and Bayesian inference) of the order Spirurida were performed to determine the phylogenetic location of this species. Primer pairs of the ITS regions were designed for genus-level identification of specimens, regardless of their cycle, as an alternative to coprological methods. The utility of this molecular method for identification of morphologically altered specimens is also discussed.

Populations of breeding birds in Byers Peninsula, Livingston Island, South Shetland Islands

AbstractData about breeding populations of birds in the Antarctica are rare and fragmented. Thus, information about the status of the breeding populations of Antarctic birds is crucial given the current scenario of climate change, which is particularly acute in Antarctica. This paper presents new information about the populations of the Antarctic tern Sterna vittata, the kelp gull Larus dominicanus, the southern giant petrel Macronectes giganteus, the Antarctic skua Catharacta antarctica lonnbergi, the chinstrap penguin Pygoscelis antarctica and the gentoo penguin Pygoscelis papua on Byers Peninsula (Livingston Island, South Shetland Islands). We used line transects counts to estimate both densities and numbers of nests of the different species. We estimate that there are 398.96 birds km-2 of southern giant petrels (2793 individuals), 62.4 birds km-2 of Antarctic tern (3746 individuals) and 269.1 birds km-2 of kelp gull (1884 individuals). Furthermore, we found 15 nests of Antarctic skua in 25 km2, from which we can estimate that 60–91 birds must breed on Byers Peninsula. We also censused two colonies of gentoo penguins (3000 and 1200 pairs) and 50 pairs of chinstrap. Compared to previous estimates, gentoo penguins seem to have increased whereas chinstrap penguin have decreased. Finally, the populations of Antarctic tern, southern giant petrel and kelp gull have stabilized or slightly increased.

Olfactory detection of dimethyl sulphide in a krill-eating Antarctic penguin

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 474:277-285 (2013) - DOI: https://doi.org/10.3354/meps10081 Olfactory detection of dimethyl sulphide in a krill-eating Antarctic penguin Luisa Amo1,*, Miguel Ángel Rodríguez-Gironés1, Andrés Barbosa2 1Departamento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas, Carretera de Sacramento s/n, 04120, La Cañada de San Urbano, Almería, Spain 2Departamento de Ecología Evolutiva, Museo Nacional de Ciencias Naturales, C/ José Gutiérrez Abascal 2, 28006, Madrid, Spain *Email: luisa.amo@eeza.csic.es ABSTRACT: In response to zooplankton grazing, phytoplankton release dimethylsulphoniopropionate in the seawater, which is then catabolized to dimethyl sulphide (DMS) that is emitted to the air. This molecule therefore signals areas of high productivity in the oceans, and it can be used by predators for locating foraging areas. Detection of this compound has been described in several species of procelariiform seabirds and non-Antarctic fish-feeding penguins. However, there is no evidence of DMS detection by krill-feeding penguins. The mechanisms of krill detection by its predators are especially relevant in Antarctica, where trophic webs are mainly based on krill. We explored for the first time whether a krill-feeding penguin species, the chinstrap penguin Pygoscelis antarctica, is able to detect DMS. We examined whether chinstrap penguins could detect DMS by locating DMS or control recipients in pathways that penguins used when moving between the colony and the sea. We also analysed the attraction of nestling penguins to DMS in a T-shaped experimental enclosure. Our results showed that adult penguins are attracted to DMS on land. Nestling penguins also tended to be attracted to the scent of DMS. Further research is needed to examine whether chinstrap penguins use natural DMS concentrations as a foraging cue at sea. KEY WORDS: Dimethyl sulphide · Avian olfaction · Antarctic penguin · Pygoscelis antarctica Full text in pdf format PreviousNextCite this article as: Amo L, Rodríguez-Gironés MÁ, Barbosa A (2013) Olfactory detection of dimethyl sulphide in a krill-eating Antarctic penguin. Mar Ecol Prog Ser 474:277-285. https://doi.org/10.3354/meps10081 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 474. Online publication date: January 31, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.

An observation of between-mates feeding behaviour in chick-guarding chinstrap penguins

Courtship feeding has not been reported for chinstrap penguins (Pygoscelis antarctica). However, we observed a male chinstrap penguin fed to his mate during the guard stage of chick. After being fed, the female regurgitated the food to her chick. Our observation suggests that the chicks’ behaviour of begging for food may be retained in adults, but it is usually restrained.

The importance of fish in the diet of the South Polar Skua (Stercorarius maccormicki) at the South Shetland Islands, Antarctica

Where South Polar Skuas (Stercorarius maccormicki) occur in the absence of Brown Skua (S. antarcticus), their main prey consists of other birds. In contrast, where the two species occur together, fish appears to dominate the diet of South Polar Skuas, probably because Brown Skuas monopolise the terrestrial resources. Twenty-eight stomach samples of South Polar Skuas were collected throughout the breeding season at Half Moon Island, South Shetland Islands, Antarctica. Fish were the most dominant prey item (100% frequency, 98% prey mass); their importance remained constant throughout the study period. Although there is a colony of Chinstrap Penguin (Pygoscelis antarctica) nearby the South Polar Skua population and there are very few Brown Skuas, the South Polar Skuas did not eat penguins. The result suggests fish are selected preferentially over terrestrial resources, at least in certain regions, and particularly when availability of terrestrial resources is limited. Thus, competitive exclusion by Brown Skuas may not fully explain dietary choice of South Polar Skuas.

Hatching order and size-dependent mortality in relation to brood sex ratio composition in chinstrap penguins

The differential environmental sensitivity of the sexes has strong implications in the evolutionary history of species as it can alter sexual size dimorphism, population sex ratios, and the faculty of parents to manipulate offspring sex in relation to environmental conditions. We studied sexual differences in hatching patterns and evaluated sex- and size-related mortality in relation to hatching order and brood sex ratios in the chinstrap penguin Pygoscelis antarctica, a moderately size-dimorphic species, with a modal clutch size of 2 eggs. We found that male, second-hatched, and large eggs showed shorter hatching periods than female, first-hatched, and small eggs. We also found a male-biased mortality of nestlings in the colony. However, male mortality patterns differed depending on the brood sex ratio composition. Mortality of male chicks in all-male broods was higher than in mixed broods and higher than female mortality in all-female broods. Contrary, females from mixed brood showed higher mortality than their male nest mates and higher too than females in all-female broods. Second-hatched chicks also suffered from higher mortality than first-hatched chicks. Our results indicate that both the superior competitive capacity and the higher energy demand of the larger sex constitute 2 causal factors explaining patterns of sex-biased mortality. Both factors occur in the same species and in different situations of sibling competition shaped by brood sex ratio composition. This study constitutes a good example of how patterns of sex-related mortality can vary depending on nest environmental circumstances. Furthermore, our study suggests that hatching period can be a mechanism underlying sexual differences in the embryonic period of birds.

Effects of variability in prey abundance on reproduction and foraging in chinstrap penguins (Pygoscelis antarctica)

AbstractLife‐history theory predicts that adults of long‐lived species such as seabirds should optimally balance investment in current and future offspring. However, when trying to optimize investment in offspring provisioning, the most energetically costly component of seabird parental care, adults need to contend with large interannual fluctuations in prey availability and hence the cost of chick provisioning. Adults faced with this uncertainty can mechanistically balance parental care by adopting a strategy somewhere along the continuum between maintaining constant investment in foraging effort between years and letting chick provisioning fluctuate or holding chick provisioning constant and varying investment in foraging effort. Using ship‐based hydroacoustic assessment of prey, time‐depth recorders attached to penguins and land‐based observations at the breeding colony, we examined how foraging and reproductive effort in breeding chinstrap penguins Pygoscelis antarctica responded to interannual variation in the abundance of Antarctic krill Euphausia superba in the vicinity of Seal Island, South Shetland Islands, 1990–1992. Regional measures of krill density varied by a factor of 2.5 (47.0, 23.8 and 61.2 g m−2 in 1990, 1991 and 1992, respectively) and was correlated with annual measures of breeding adult body weight and reproductive performance (breeding population size, duration of chick rearing, chick growth, breeding success and fledgling weight). In contrast, measures of penguin foraging effort (dive depth, dive duration, number of trips day−1, trip duration, number of dives trip−1 and dive rate) did not differ between years. We conclude that chinstrap penguins reduce reproductive success rather than increase foraging effort in response to decreases in prey abundance in a manner consistent with predictions of life‐history strategies for long‐lived seabirds.

Polybrominated diphenyl ethers, polychlorinated dibenzo-dioxins,-furans, and-biphenyls in three species of antarctic penguins

Fish-eating seabirds are recognized to be at risk of accumulating toxic contaminants due to their high position in the trophic web and to their low ability to metabolize xenobiotic compounds. Penguins are widely distributed in Antarctica and represent an important fraction of the Antarctic biomass. They feed mainly on krill and, depending on krill availability, also on fish. It has been reported that predators may be a sink for volatile and toxic chemicals and this may pose a serious environmental problem. Polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-dioxins (PCDDs), -furans (PCDFs), and -biphenyls (PCBs), including non-ortho congeners, hexachlorobenzene (HCB) and p,p'-DDE, were quantified in three species of Antarctic Pygoscelids in order to evaluate their accumulation patterns. The potential toxicity of twenty-two dioxin-like congeners was assessed and expressed as 2,3,7,8-tetraCDD equivalents (TEQs). Differences between males and females were investigated. Blood samples of the Adélie penguin Pygoscelis adeliae, Chinstrap penguin Pygoscelis antarctica and Gentoo penguin Pygoscelis papua were collected at Admiralty Bay, King George Is (62 degrees 10'39" S, 58 degrees 26'46" W) in February 2004. Halogenated hydrocarbons were identified and quantified using gas chromatography coupled with gas chromatography mass spectrometry analyses. Results are expressed on a wet weight basis. HCB, p,p'-DDE and sigmaPCBs were higher in Adélie penguins (6.7 +/- 6.1, 8.2 +/- 3.3 and 9.8 +/- 3.8 ng/g, respectively) than in Chinstrap and Gentoo penguins, both of which showed values in the same order of magnitude, but approximately 40% lower than Adélie penguins. Hexa-CBs ranged 35-45% of the residue. Low-chlorinated PCBs (nos. 70+76+95+ 56+60+101) accounted for 40-60% in the three species. PCB101 made up 15% of the residue in Adélie penguins. PBDEs were 291 +/- 477, 107 +/- 104 and 116 +/- 108 pg/g in Adélie, Chinstrap and Gentoo penguins, respectively; the most abundant congeners were BDE47 in Adélie and Chinstrap penguins and BDE17 in Gentoo penguins. PCDDs were 22 +/- 32, 6.5 +/- 7.4 and 18 +/- 23 pg/g in Adélie, Chinstrap and Gentoo penguins, respectively. PCDFs were higher in Adélie penguins and lower in Chinstrap penguins. PCDDs/Fs and PBDEs were higher in males than in females of Gentoo and Chinstrap penguins; differences in concentrations were likely related to the partial detoxification that occurs in females during egg formation. Of the four non-ortho PCBs measured, PCB126 occurred at the highest concentrations and contributed the majority of the non-ortho PCB-TEQ in Gentoo and Chinstrap penguins. The highest TEQs were found in the Gentoo penguin and due mainly to PCDDs and non-ortho PCBs. POP concentrations in penguins were lower than those found in seabird species from other areas of the world. Different chemical accumulation patterns were observed in relation to species and sex; the Adélie penguin showed the highest POP levels. Dissimilar ecological or metabolic features may be involved; the diverse timing of reproduction steps can be responsible for those differences; moreover, Adélie penguins feed on krill (a fatty resource) more abundantly than the other two species during the rearing period. The South Shetland Islands might be subjected to a higher chemical impact with respect to the rest of Antarctica, due to their being near South America. Because penguins are fish-eating birds showing low detoxifying capacities and key-species in Antarctic ecosystems, further studies on their xenobiotic metabolism should be carried out.

Spatial distribution of predator/prey interactions in the Scotia Sea: implications for measuring predator/fisheries overlap

Abstract The measurement of spatial overlap between predators and fisheries exploiting a common prey source is dependent upon the measurement scale used; inappropriate scales may produce misleading results. Previous assessments of the level of overlap between predators and fisheries for Antarctic krill ( Euphausia superba ) in the region of the South Shetland Islands used different measurement scales and arrived at contradictory conclusions. At-sea data from observations of krill predators during the CCAMLR 2000 Survey were used to identify the areas of potential overlap with fisheries in the Scotia Sea and to determine the scale at which such overlap should be measured. The relationship between autocorrelation and sampling distance was used to identify the characteristic scales of the distribution of predators, krill and krill fisheries, and an effort-corrected index of relative abundance as a function of distance from land was used to identify the characteristics of areas of high potential for overlap. Despite distinct differences in foraging ecology, a group of krill-dependent species including chinstrap penguin ( Pygoscelis antarctica ), (Antarctic) fur seal ( Arctocephalus sp. ( gazella )) and white-chinned petrel ( Procellaria aequinoctialis ) showed similar patterns of distribution; the relative abundances were highest at 60–120 km from land and decreased sharply at distances greater than 150 km from land. There were more inter-specific differences in the characteristic scales, which were of the order of 50–100 km. Antarctic krill had a characteristic scale of approximately 200 km and the relationship with distance from land showed a log-linear decline. Krill fisheries operate at a scale of 150 km and occur almost entirely within 100 km of land. The requirement of land for breeding and the biological and oceanographic conditions that produce the high concentrations of krill associated with those land areas produce a system in which the demand for Antarctic krill from fisheries and predators is essentially co-extensive. The areas of greatest potential overlap are within 150–200 km of land and to accommodate the scales of operation of the processes involved the extent of such overlap in these areas should be assessed at scales of 70–100 km.

Nest size and hatchling sex ratio in chinstrap penguins

Variation in the sex ratio at hatching in the chinstrap penguin Pygoscelis antarctica was investigated, using molecular sexing to test predictions of sex allocation theory. The sex ratio was slightly male-biased (0.54) but did not differ significantly from parity. The proportion of males increased with nest size, an estimator of parental quality in chinstrap penguins. High-quality parents were able to produce and rear a higher proportion of male offspring, the more costly sex in this slightly sexually dimorphic species. Our results may be in agreement with Trivers and Willard’s (1973) argument on biases in the offspring sex ratio being contingent on parental condition or quality.

Causal and functional correlates of brood amalgamation in the chinstrap penguin Pygoscelis antarctica : parental decision and adult aggressiveness

Despite the high number of species in which crèching behaviour has been analysed, the factors determining brood desertion and chick aggregations remain relatively poorly understood. We analysed crèching behaviour of chinstrap penguins (Pygoscelis antarctica) to test whether: (1) timing of chick aggregations was mainly determined by the growth stage of chicks or by adult physiological constraints; (2) the crèche acts as a protective mechanism against predation or as a defence against conspecific adult aggressiveness. Our results show that chick desertion was not related to chick growth rate and was driven primarily by a parental decision, determined by adult physical constraints imposed by moulting needs and the short breeding season in Antarctica. With respect to the functional meaning of brood amalgamations, our results suggest that they are originated by the aggressive behaviour of adults, although the forces driving them could depend greatly on ecological conditions and vary among species and populations. Finally, because brood amalgamations can be determined by adult aggressiveness contrasting with the origin and typical definition of the term "crèche" (which implies the nursery concept), we propose the use of the term "brood amalgamation" for the penguin "crèches".

Plasma chemistry of the chinstrap penguin Pygoscelis antarctica during fasting periods: a case of poor adaptation to food deprivation?

The chinstrap penguin (Pygoscelis antarctica) is the smallest penguin species to be used to study the physiology of fasting. We analysed body-mass change and plasma chemistry of five non-breeding chinstraps during an experimental fasting period in the breeding season. We also analysed the same parameters in six fasting birds under natural conditions (during an incubation shift, which lasts about 10 days). Both groups presented similar patterns of change, showing a rapid increase in urea and uric acid plasma concentrations. Urea surpassed 3 mmol/l after 5 fasting days, while uric acid reached 1 mmol/l after 9 days. Plasma glucose levels decreased after 11 days, whereas cholesterol also showed a clear reduction during fasting. These results as a whole suggest that chinstrap penguins reached phase III after a short period in comparison with other Pygoscelis species. Body size and ecological factors could explain these inter-specific differences.

Adult aggression during the post-guard phase in the chinstrap penguin Pygoscelis antarctica

We report an observational study of aggressive behaviour by adults during the post-guard phase in the chinstrap penguin. The study was carried out in one subcolony where all the individuals (breeders, chicks and failed breeders) were banded, as well as in nine other subcolonies where individuals were not identifiable. Breeding adults were more aggressive towards unrelated chicks when they were feeding their own chicks than in other contexts. Chicks were also attacked at high rates by adults that did not belong to their own subcolonies. The evidence suggests that some aggressions to chicks by adults may function to avoid interference from unrelated chicks during food transfers, but our data also show that aggressive interactions are common in contexts other than chick feeding. However, aggression by adults did not show any clear spatial directionality or purpose of shepherding the chicks, and these tended not to move in any particular direction when attacked.

Individual Diving Behavior, Food Availability and Chick Growth Rates in Chinstrap Penguins

-The relationship between foraging effort and chick growth rate was investigated in two Chinstrap Penguins (Pygoscelis antarctica), fitted with time-depth recorders and whose diving behavior differed from each other. Foraging effort did not differ between the individuals, but the growth rates of their chicks differed. Although these birds bred at the same colony and at the same time, food available to the parents differed because of the depth at which they fed and this possibly was reflected in the growth of the chicks. Food availability depends on the abundance of potential food and also on the feeding behavior of individuals. Received 16 March 2001, accepted 20 May 2001.

Factors that affect hatching asynchrony in the chinstrap penguin ( Pygoscelis antarctica )

We examined if laying intervals and hatching asynchronies are related in a chinstrap penguin (Pygoscelis antarctica) population in the South Orkneys. The lack of association between the two variables, as well as data on brood patch development, indicated that incubation did not begin immediately after the first egg was laid. This suggests that longer laying intervals may be compensated by longer delays in the onset of full incubation. Hatching asynchrony increased with within-clutch egg size asymmetry, decreased with breeding date, and was related to the laying order of the eggs according to size. However, only egg-size asymmetry remained significant when controlling for the other variables. We conclude that more asymmetric clutches were more asynchronous, although a large part of the variation in hatching asynchrony remains unexplained.

Bill Size in Relation to Position in the Colony in the Chinstrap Penguin

-In most seabirds, breeding success can be related to the ability to obtain a suitable nest-site within the colony, and this may result in competition for the limited number of available sites. Thus, if nest-sites vary in quality, individuals of the same sex are expected to compete for access to the highest quality nest-sites to enhance their own fitness. It is therefore expected that intrasexual competition would result in a correlation between size in the competing sex, or the size of a trait used as a weapon, and nest quality. Chinstrap Penguins (Pygoscelis antarctica) fight with other conspecifics using the bill as a weapon. If bill size provides an advantage for intra-specific combat, we would expect stronger bills in males occupying the best nest sites. We studied patterns of some adult morphological traits in relation with nest position in a colony of Chinstrap Penguins. Bill morphology was related to nest position in the colony, with individuals occupying the central positions having the deeper bills. This relationship was found in both sexes. Our data suggest that competition for position within the colony is not an important factor involved in the sexual dimorphism shown by the Chinstrap Penguin. Received 31 August 2000, accepted 1 October 2000.

Absence of extra-pair fertilisations in the Chinstrap Penguin Pygoscelis antarctica

We analysed genetic relatedness through DNA-fingerprinting in 38 two-chick families of Chinstrap Penguins Pygoscelis antarctica in the Vapour Col colony on Deception Island, Antarctica. Band-sharing coefficients between males and chicks in their nests, females and chicks in their nests and brood mates were very close to 0.50 and were not significantly different. Presumably unrelated pair mates showed much lower band-sharing coefficients (0.12), which differed significantly from those between putative parents and their chicks and between presumed siblings. No case of extra-pair paternity was detected according to the presence of novel bands or to band-sharing coefficients. Monogamy in the study population is not only social but also genetic.