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A small colony of black-browed albatrosses (Thalassarche melanophris, 21–65 breeding pairs) was discovered in 2003 on Albatross Islet, Tierra del Fuego, Chile. The formation of new breeding sites is important from an ecological and evolutionary perspective. This colony is particularly significant because it is the only one recorded for the species in a land-locked area. As its population dynamics could be shaped by stochastic and other factors affecting small populations, understanding the variables influencing its persistence, such as source of breeders, is crucial. Here, we used genetic markers (mitochondrial control region) to determine the origin of individuals at this new breeding site. Our results show that the new colony is an even mix of birds from Chilean colonies to the south and west (52%) and Falklands/Malvinas birds to the east (48%). Understanding the unique characteristics of this colony provides valuable insights for the conservation of black-browed albatrosses given increasing anthropogenic and environmental changes. [ABSTRACT FROM AUTHOR]

Climate change is a major concern for the future of marine Arctic food webs. Diet shifts of seabirds can be used as indicators of environmental changes such as species compositions of food webs. However, studies on diets are often laborious and costly, while research in vulnerable Arctic environments benefits from short visits for data collection that minimize disturbance to Arctic wildlife and the environment. DNA-metabarcoding techniques are rapidly developing and could be used as an effective method of monitoring diet choice of seabirds. We tested DNA-metabarcoding on seabird faeces collected during short visits of typically around 30 min at breeding colonies of black-legged kittiwake Rissa tridactyla (3 colonies), Brünnich's guillemot Uria lomvia (2 colonies) and little auk Alle alle (3 colonies). DNA metabarcoding based on COI and 18S of a limited number of faeces samples revealed a wide spectrum of fish species and crustaceans in the diets of these species, comparable with or even exceeding diversity in diet composition found in conventional, more invasive techniques where birds are shot or caught and handled to obtain samples. While previous studies on diet choice of little auk, a crustacean specialist, mainly report small fractions of unidentified fish remains, DNA metabarcoding of faeces revealed a large variety of pelagic and benthic fish species supplementing its diet. We conclude that DNA metabarcoding of seabird faeces can be an effective attribute to diet studies supporting our understanding of changes in numbers and distribution of Arctic seabirds and their marine environment. [ABSTRACT FROM AUTHOR]

An essential trait in the life history of any animal species is reproduction, including parental care. In seabirds, these actions are well defined and stereotyped. Our study focused on analyzing the parental care behavior, reproductive success, and phenology of the southern rockhopper penguin (Eudyptes chrysocome chrysocome) population of Isla Pingüino, Argentina, through the use of autonomous time-lapse cameras combined with marking of individuals. We compared our results to data obtained from traditional monitoring methods used in the same colony. The phenology of their breeding cycle was the same as in other colonies of the SW Atlantic region. Although parents shared their chick rearing duties, females invested more time in incubating the eggs, while males were more dedicated to chick guarding. Chicks were more frequently fed by females, and males contributed only during the crèche period. The effect of heat stress on chick survival was assessed, since uncommonly high air temperatures were reached during the study, causing unprecedented chick mass mortality. Temperatures of > 25° C were a lethal threshold for chicks; hence, the occurrence of several extremely hot days increased chick mortality. Our combined methodology was useful to evaluate phenology, parental investment, and the variables that affect reproductive success (for instance, weather conditions). We recommend its use in future comparative and long-term studies at remote rockhopper penguin colonies to help improve the quality of monitoring and detect potential threats of this vulnerable species. [ABSTRACT FROM AUTHOR]

Seabirds often spend time on the water in the vicinity of their breeding colonies at the start or end of foraging trips, which may be for bathing, social interaction, information transfer, or to reduce predation risk for small petrels that prefer to return to land in darkness. Although such behaviour (hereafter rafting) is common, there are few data on variation in its incidence or timing across species, or analyses of relationships with intrinsic or extrinsic factors such as breeding stage (reflecting central-place foraging constraints) or weather. Here, we use GPS and immersion data collected over multiple years at Bird Island, South Georgia, to investigate rafting behaviour of four albatross and one burrow-nesting petrel species. Nearly all tracked birds (89%) landed within 10 km of the colony at the start of foraging trips for ~ 30 min, whereas only 17% did so at the end, suggesting they likely use rafting mainly for plumage maintenance after extended breeding shifts on land. Rafting duration, distance and bearing from the colony varied markedly according to species, wind speeds and period of the day (daylight vs. darkness), which may reflect differences in foraging direction, time constraints, degree of plumage soiling, diel activity patterns, or the requirement for high wind speeds for efficient flight. Given that all the study populations are decreasing, and most individuals make extensive use of nearshore waters during the breeding season, effective marine spatial planning is required that eliminates or mitigates human risks around their colonies. [ABSTRACT FROM AUTHOR]

This paper provides data on a newly discovered colony of Magellanic penguins Spheniscus magellanicus in the southwest Atlantic Ocean. A new settlement was found while conducting southern rockhopper penguin Eudyptes chrysocome studies in the San Juan de Salvamento colony in Staten Island, Argentina. The colony holds 88 breeding pairs. While the origin of the founders was unknown, it is possible that they came from the nearby Observatorio Island colony located ~ 20 km away. New colonies allow populations to expand and establish in new areas, which could allow a species to respond to changes in climate. Nonetheless, this expansion might be a detriment to other penguin species that already occupied the area. [ABSTRACT FROM AUTHOR]

The use of combined conventional and stable isotope analyses (SIA) to study the diet of seabirds has become very frequent. Unfortunately, information on the trophic ecology of immature seabirds remains scarce because the sampling of tissues to perform SIA is often very limited due to the difficulty to capture these birds. The koilin membrane, which covers the regurgitated pellet casts of some seabirds, could offer an interesting non-intrusive alternative tissue to perform SIA. In this two-year study of the diet of imperial cormorants in southern Patagonia, we (1) compare the diets of breeding and non-breeding birds through conventional pellet analysis; (2) describe the diet of breeding adults and chicks through a combined method of pellet analysis and whole blood SIA; and finally, (3) compare SIA values of breeding adults obtained from blood with those obtained from koilin membranes. We found that immature individuals incorporated abundant invertebrate taxons, compared with breeding adults which relied mainly on fish. Younger and inexperienced individuals, which are not under the constraint to feed chicks, are feeding on more predictable, but lower trophic and less energetic prey. By comparing the stable isotope values of koilin and blood in breeding adults, a correlated interannual difference between the two seasons was found. Under the light of our results, the koilin offers an encouraging alternative to blood in the study of trophic ecology, particularly for ages or stages in which capture is not possible. [ABSTRACT FROM AUTHOR]

The Little Auk Alle alle is a small planktivorous auk breeding colonially in the High Arctic. Owing to its large population size and bi-environmental lifestyle, resulting in the large-scale transport of matter from sea to land, the Little Auk is one of the most important components of the marine and terrestrial ecosystems in the Arctic. As a result of globalization, which facilitates access to remote areas of the Earth, a growing number of studies is being dedicated to this endemic Arctic seabird. Research has focussed primarily on the importance of the Little Auk as an ecological indicator reacting to the climatic and oceanological changes that are particularly evident in the Arctic as a result of Arctic amplification (warming is more rapid in the Arctic than in any other region on Earth). Importantly, the species is also used as a model to investigate matter and energy flow through the ecosystem, mate choice, parental care and biological rhythms. Here, we review the natural history of the Little Auk, highlighting studies with the potential to provide answers to universal questions regarding the response of seabirds to climate variability and avian reproductive behaviour, e.g. threshold of foraging flexibility in response to environmental variability, carry-over effects between the breeding and non-breeding periods, the reasons for the transition from bi- to uni-parental care, parental coordination mechanisms. [ABSTRACT FROM AUTHOR]

While decreases in Arctic sea ice affect all marine communities in the Arctic Basin, the effects are greatest on the cryopelagic ecosystem and species with critical life history stages dependent on the presence of sea ice. During the recent and ongoing period of rapid sea ice loss these species have been subject to spatial and temporal disruptions requiring behavioural plasticity. Mandt's Black Guillemots (Cepphus grylle mandtii) is one of the few ice-obligate Arctic seabirds. Polar cod (Boreogadus saida) is their preferred prey. We monitored their prey selection and diving behaviour during the annual period of chick provisioning from 2011 to 2017, to assess their ability to respond to the now common seasonal loss of sea ice and increased water temperature in their nearshore foraging area. The percentage of polar cod fed to nestlings decreased with increasing SST, with fourhorn sculpin (Myoxocephalus quadricornis), a nearshore demersal, becoming common (20% of deliveries) with SST > 2.0 °C and comprising more than half of the prey when SST > 3.4 °C. This prey-switch coincided with a marked increase in dives and time underwater per day and a decrease in dive duration as birds switched to nearshore, benthic habitats. Sea ice is declining and SST increasing throughout the Arctic Basin and other upper-trophic level predators dependent on polar cod could be expected to be exhibiting similar prey-switching and modifications in foraging effort. [ABSTRACT FROM AUTHOR]

Small petrels are the most abundant seabirds in the Southern Ocean. However, because they breed in burrows on remote and often densely vegetated islands, their colony sizes and conservation status remain poorly known. To estimate the abundance of these species on Bird Island in the Falkland archipelago, we systematically surveyed their breeding burrow density and occupancy across this near-pristine tussac (Poa flabellata)-covered island. By modelling burrow density as functions of topography and Sentinel 2 satellite-derived Normalised Difference Vegetation Index data, we inferred habitat associations and predicted burrow abundance of the commonest species—Thin-billed Prions (Pachyptila belcheri) and Wilson's Storm-petrels (Oceanites oceanicus). We estimate that there are 631,000 Thin-billed Prion burrows on the island (95% CI 496,000–904,000 burrows). Assuming that burrow occupancy lies between 12 and 97%, this equates to around 76,000–612,000 breeding pairs, making Bird Island the second or third largest P. belcheri colony in the world, holding approximately 3–27% of the species' breeding population. We estimate that 8200–9800 (95% CI 5,200–18,300 pairs) pairs of Wilson's Storm-petrels also breed on the island. Notably, the latter burrowed predominantly under and within tussac pedestals, whereas they are usually assumed to breed in rock cavities. Thin-billed Prions are declining in the Kerguelen archipelago, but their population trends in the Falklands are unknown. Given the wide confidence intervals around our own and other population estimates for these cryptic species, we recommend that their populations should be monitored regularly, at multiple sites. [ABSTRACT FROM AUTHOR]

Surveying seabirds in polar latitudes can be challenging due to sparse human populations, lack of infrastructure and the risk of disturbance to wildlife or damage to habitats. Counting populations using un-crewed aerial vehicles (UAVs) is a promising approach to overcoming these difficulties. However, a careful validation of the approach is needed to ensure comparability with counts collected using conventional methods. Here, we report on surveys of three Antarctic bird species breeding on Signy Island, South Orkney Islands; Chinstrap (Pygoscelis antarctica) and Gentoo (Pygoscelis papua) Penguins, and the South Georgia Shag (Leucocarbo atriceps georgianus). We show that images from low-altitude UAV surveys have sufficient resolution to allow separation of Chinstrap Penguins from contiguously breeding Adélie Penguins (Pygoscelis adéliae), which are very similar in appearance when viewed from overhead. We compare data from ground counts with manual counts of nesting birds on images collected simultaneously by low-altitude aerial photography from multi-rotor UAVs at the same colonies. Results at this long-term monitoring site confirmed a continued population decline for Chinstrap Penguins and increasing Gentoo Penguin population. Although both methods provided breeding pair counts that were generally within ~ 5%, there were significant differences at some locations. We examine these differences in order to highlight potential biases or methodological constraints that should be considered when analysing similar aerial census surveys and comparing them with ground counts. [ABSTRACT FROM AUTHOR]

Gentoo penguins (Pygoscelis papua) have a widespread breeding distribution across the sub-Antarctic and Antarctic. Population trends vary across their range, with increases recorded in the Antarctic and Atlantic sectors of the Southern Ocean, while other sub-Antarctic populations are decreasing. Macquarie Island is the only breeding site for gentoo penguins in the Pacific sector of the Southern Ocean and one of just two breeding sites within Australian territories. Eight island-wide censuses were undertaken between 1984 and 2017 to estimate the number of breeding pairs, with a follow-up chick census conducted in four years to calculate breeding success. The most recent census in 2017 recorded the fewest breeding pairs since counts began, with 2527 ± 66 gentoo pairs island wide. However, breeding success was the highest recorded at 0.99 chicks per nest. Trends in sub-populations around the island differed. However, island-wide breeding pairs have decreased by − 1.8 ± 0.4% per annum over the past 34 years, particularly driven by breeding colonies in the east-coast section of the island. This overall negative trend differs from the currently stable global trend, but mirrors what is happening in some other parts of the species' sub-Antarctic range. We suggest based on a 50% decrease in breeding pairs over the species' last three generations, and a lack of recent data from Heard Island, Australia's other gentoo penguin breeding site, the species be considered for listing under the Australian Environment Protection and Biodiversity Conservation Act 1999. [ABSTRACT FROM AUTHOR]

The current information about the diet composition of the rock shag (Phalacrocorax magellanicus) in the SW Atlantic coast comes mainly from conventional pellet or stomach content analysis from a few locations situated in northern Patagonia (Chubut Province, Argentina). In this work, we studied the diet of breeding rock shags over several years at a colony from southern Patagonia (Ría Deseado, Santa Cruz Province, Argentina) using a combined technique of conventional diet assessment (pellet analysis) and stable isotope analysis of carbon and nitrogen. Our results confirm the importance of benthic prey and the low inter-annual variability in the diet of the rock shag. These results coincide with previous research in relation to the exploitation of slow moving, predictable, but low-energy density prey. The stable isotope mixing models, which was informed with prior data obtained from pellet analysis, allowed for the detection of subtle differences between the diet of adults and chicks, consisting in the incorporation of higher proportions of cephalopods, an energy-rich prey, in the diet of chicks. By comparing our results with the diet of the red-legged cormorant, which breeds in sympatry in the Ría Deseado Estuary and whose diet composition is strongly pelagic, we suspect a certain level of trophic resource partitioning between these rock shag and red-legged cormorant. [ABSTRACT FROM AUTHOR]

Monitored seabird populations—useful sentinels of marine ecosystem health—have been declining worldwide at a rapid pace. Yet, lack of reliable long-term monitoring data constrains assessment of the conservation status of many seabird populations. Unmanned aerial vehicles (UAVs) have the potential to increase survey efficiency and count precision of seabird populations, especially where time constraints or inaccessible terrain, such as sea stacks, limit meaningful ground-based surveys. Furthermore, tremendous potential exists to combine fine-scale spatially integrated habitat mapping obtained from UAV images with occupancy to unravel how abiotic factors such as topography affect animal populations. In late December 2018, we used an UAV to create a georeferenced orthomosaic image and digital elevation model (DEM) from which we determined the size of the Antarctic shag (Leucocarbo bransfieldensis) breeding colony at Harmony Point, Nelson Island, South Shetland Islands. Our population estimate of 69 breeding pairs is approximately double that reported for the early 2000s and the highest count since the late 1980s. Most nests were located 10 to 20 m above sea level, on relatively shallow gradients that predominantly faced southeast. While it is difficult to compare historical ground-based counts with the UAV-derived estimates presented here, our new data provide robust baseline information for future monitoring of the colony population size using comparable survey methods. Our basic mapping of the topography of the breeding colony also highlights how UAV-derived habitat information can facilitate our understanding of the influence of landscape structure on animal population dynamics. [ABSTRACT FROM AUTHOR]

In several parts of Antarctica, the information on the size of seabird populations is outdated by decades. Considering the environmental changes taking place at the Antarctic Peninsula, up-to-date information is urgently required. In this study, the breeding population of southern giant petrel (Macronectes giganteus) at Harmony Point, Nelson Island, was counted and mapped during incubation. The total number of active nests was 481, distributed mostly in small dispersed groups (< 30 nests); one single colony presented > 100 nests. Nests were distributed throughout the whole area. Current colony distribution was similar to the ones reported previously. The current number of nests is similar to those reported since 2005, and also for early counts in the 1965 and 1989s. However, current numbers were almost half of those counted in the 1997. The apparent increases in the number of southern giant petrels by 1997 was attributed to prohibiting tourism visits to the area (giant petrels are sensitive to human disturbance), but causes of the following decrease are unknown. This highlights the need for updated information in order to understand which factors are responsible for trends in Antarctic seabird populations. [ABSTRACT FROM AUTHOR]

The Black-browed Albatross (BBA, Thalassarche melanophrys) and the Grey-headed Albatross (GHA, Thalassarche chrysostoma) are long-lived sympatric species breeding in the Atlantic and Pacific sections of the Southern Ocean. While the Atlantic populations of these two species have been the subject of several studies, little information is available on the most important colonies in the Southeast Pacific Ocean (Chile). The presence of parasites in these long-lived hosts has been described for the colonies in the Southern Atlantic, but not in those from Chile. Therefore, the objective of this study was to identify ectoparasites and hemoparasites associated with both species breeding in the Diego Ramírez Archipelago (56°S) in Southern Chile. Chicks were examined for ectoparasites during the breeding seasons in 2010 and 2011 (GHA, n = 80; BBA, n = 40). Parasites were collected manually, mounted, and identified to species level. The sex and developmental stage of adult ectoparasites were also determined. Ectoparasites were detected on 78.75 and 32.50% of GHA and BBA chicks, respectively. A total of 126 ectoparasites were obtained: 103 Ixodes uriae ticks (GHA 79.62%, BBA 20.38%); 22 Parapsyllus longicornis fleas (GHA = 31.8%, BBA = 68.2%); and a single Austromenopon affine louse (found on GHA). Diego Ramírez represents a new record and distribution range for I. uriae and A. affine. The presence of hemoparasites was explored on blood smears for GHA ( n = 26) and BBA ( n = 119), but none were recorded in either of these albatrosses. [ABSTRACT FROM AUTHOR]

The Arctic tern ( Sterna paradisaea) is a well-known polar seabird which breeds around the circumpolar Arctic, and which undertakes the longest known annual migration of any organism. Despite its familiarity, there is little information on its breeding biology in the High Arctic, an important baseline against which future studies of climate change impacts on northern wildlife can be compared. We studied the breeding biology of Arctic terns in the Canadian High Arctic during five field seasons, and compared this to breeding biology of terns from more southern parts of its range. Because our field site was beside a productive polynya, we expected that reproductive metrics for terns nesting there would be relatively high. However, mean clutch size (1.7 eggs), mean egg size (40.2 mm × 29.0 mm), mean nest initiation dates (6 July) were similar to Arctic terns breeding elsewhere. With our data, we could not assess the independent effects of predation pressure, poor weather or low food supplies, but two years with low tern reproduction were also years with low adult body mass and low clutch size (indicating poor food supplies), as well as low hatching success and high nest abandonment (possibly due to high predation pressure). [ABSTRACT FROM AUTHOR]

In this study, we investigate the numbers, productivity and territory distribution of the two species of skuas (brown Stercorarius lonnbergi and south polar Stercorarius maccormicki) breeding at Signy Island, South Orkneys, and compare the results with trends elsewhere. Comparison with previous counts indicates a biphasic increase in brown skuas at Signy Island; much faster from 1958/1959 to 1982/1983 (3.3 % per annum), than in subsequent years (0.4 % per annum from 1983/1984 to 2013/2014). Relative distribution of territories has changed little over time. The reduced rate of population growth in recent years was broadly coincident with a decrease in numbers of penguins (and therefore potential prey), which may also explain recent reductions in skua numbers at other Antarctic sites. As prey have become limiting, breeding success of brown skuas at Signy Island is now slightly lower than in the 1950s/early 1960s, but timing of breeding does not appear to have changed. Brown skuas at Signy Island may still have enough resources to start breeding, but as the season progresses and availability of resources declines, chick survival is reduced. South polar skuas have declined from ten pairs in 1982/1983 to one pair in 2013/2014, and mixed pairs have increased from one to three pairs. A review of the literature indicated that although population trend data are available for relatively few sites elsewhere in the subantarctic and Antarctic, numbers of brown skuas appear to be generally decreasing or stable, and of south polar skuas to be stable or increasing. [ABSTRACT FROM AUTHOR]

Commercial fisheries currently pose a serious threat at sea to the conservation of a number of pelagic seabirds. However, these interactions are complex, and reports on population-specific bycatch in the high seas are scarce. Here we report the case of an Indian yellow-nosed albatross Thalassarche carteri re-sighted on Amsterdam Island after an apparent capture by an Indonesian long-liner, as indicated by a message attached to the bird. This record demonstrates that Amsterdam birds may interact with long-liners indeed, at least during winter, and that such interactions are not systematically lethal. We suggest that bycatch sub-lethal effects should be investigated at colonies with high risks of individual capture at sea. [ABSTRACT FROM AUTHOR]

Major population changes of marine mega-fauna are ongoing as global warming, and other anthropogenic drivers affect prey availability. The historical stronghold of the Eastern Rockhopper Penguin ( Eudyptes chrysocome filholi) was New Zealand's sub-Antarctic Campbell Island, but the population declined by 94 % between 1942 and 1984. The apparent mechanism of collapse was warm ocean temperatures causing an inadequate food supply. Eudyptes penguin population declines are ongoing at some breeding sites, highlighting the need to investigate the population trend on Campbell Island since 1984. We estimated the Eastern Rockhopper Penguin breeding population size through physical and photo-counts of birds and nests in 2012, and changes in colony area relative to 1984 and 1996 photographs. We estimated the 2012 population size at 33,239 breeding pairs, a 21.8 % decrease from an (adjusted) estimate of 42,528 pairs in 1984. Although substantial, the recent 1984-2012 decline occurred at a much slower rate ( λ = 0.991) than the 1942-1984 decline ( λ = 0.940). Despite great variation in trends between colonies ostensibly linked to differences in predation rates, the recent decline occurred primarily between 1984 and 1996, and thereafter the overall population grew. A 100-year time series of extended reconstructed sea surface temperatures (ERSST) confirmed that the population declined during warm periods and increased during cool periods, but that the initial decline began before increases in regional ERSST. Population growth after 1996 appears related to the current global warming hiatus, lower ERSST, and increased abundance of a key prey species. We predict a continuation of the long-term population decline after warming resumes. [ABSTRACT FROM AUTHOR]

Seabird life history is typified by low fecundity, high adult survival rates, and relatively long lives. Such traits act as buffers, enabling persistence of populations under variable environmental conditions. Numerous studies, however, have suggested strong sensitivity of seabirds to environmental variability. In the Antarctic Peninsula region, for example, Adélie penguin ( Pygoscelis adeliae) populations have declined during the last three decades, attributed largely to rapid changes in environmental conditions and food availability. We use 30 years of mark-recapture data from known-age individuals in the South Shetland Islands and capture-mark-recapture models to estimate survival rates with respect to such environmental variation. We investigated specifically whether negative trends in survival rates were evident and whether indices of global, regional, and local environmental conditions considered important for Adélie penguin survival explained the variability in survival rates. Overall, negative trends in juvenile survival were evident, but adult survival rates exhibited high interannual variability. Indices of sea ice extent had the strongest correlations with survival rates, particularly Weddell Sea ice extent during spring among adults ( r = 0.62) and during winter for juveniles ( r = 0.46). An analysis of deviance, however, suggested that single environmental covariates explained <30 % of the observed variation in the full mark-recapture models. Despite positive effects of sea ice extent on survival rates of Adélie penguins, limited explanatory power of several environmental conditions previously identified as important for Adélie penguin survival underscores the difficulty of predicting future population responses in this region of rapid environmental change. [ABSTRACT FROM AUTHOR]

Glucocorticoids participate in the control of whole body homoeostasis and an organism's response to stress. Corticosterone, which is the principal glucocorticoid in birds, has been shown to increase in response to different energetic demands and perturbations that individuals have to cope with. In this study, a non-invasive method to examine the corticosterone secretion by measuring faecal corticosterone metabolites (FCM) has been established for an Arctic seabird, the Little Auk ( Alle alle). A group-specific immunoassay was successfully validated for adults and chicks using an adrenocorticotropic challenge test. Then, FCM levels were investigated under different energetic and physiological demands, determined by weather conditions, week of chick rearing in adults, and age in chicks. The amount of rainfall had no effect on FCM levels in adults, whereas it negatively affected FCM levels in chicks. There was no variation in FCM concentrations among weeks of chick rearing in adults. In chicks, the FCM levels increased with age. Moreover, chicks with higher FCM levels had lower body mass and fledged later than chicks with lower FCM levels. This study demonstrates that environmental stress such as poor weather conditions can trigger significant changes in corticosterone levels in seabird chicks. Furthermore, the results indicate that corticosterone may be involved in the physiological and behavioural adjustments necessary for successful fledging and post-fledging survival. [ABSTRACT FROM AUTHOR]

To date, the knowledge of the helminth communities of Antarctic birds is scarce or fragmented. Knowledge about diseases and parasites is crucial for understanding and managing ecosystems, particularly in isolated areas where host species are more sensitive to new diseases or parasite infections. It has been showed that variations in rate of parasitism may occur between populations of host species. Two major non-exclusive hypotheses have been proposed to explain such variability: exposure to parasitism and, perhaps more important, life history strategies of hosts. We studied the helminth community of the Kerguelen Shag Phalacrocorax verrucosus, an endemic seabird species of the Kerguelen Archipelago. We provide new data on the helminths infecting this species from partial or complete digestive tracts of two birds. Two nematodes ( Contracaecumrudolphii s.l. and Ingliseria cirrohamata) were found free or attached to the wall of the proventriculus of birds, while the acanthocephalan Corynosoma sp. and the cestode species Tetrabothrius sp. occurred in the intestine of the shags. The genus Tetrabothrius is reported for the first time in Kerguelen Shags and in this area. The analysis of stomach contents from 41 live Kerguelen Shag individuals revealed infection by Contracaecum nematodes. The proportion of infected birds differed between colonies, possibly in relation to differential exposure to infected fish hosts. [ABSTRACT FROM AUTHOR]

A 118-cm-long and well-preserved sediment profile in a paleo-notch, which was formed by ocean wave action before rising to the terrace, was collected from the first terrace of Ny-Ålesund, Svalbard, Arctic. The bottom of this profile was dated as 9,400 years B.P. based on two radiocarbon dates of fossil mollusc shell fragments. The organic material in the sediment was identified by δ13Corg–C/N plot and δ15Norg characteristics to be predominantly composed of seabird guano, which was transported from the ocean via preying and excreting by seabirds. These results indicate that seabirds have inhabited Ny-Ålesund since 9,400 years B.P. after Kongsfjorden was completely deglaciated. This is the first report on Holocene seabird occupation on Ny-Ålesund and it provides the foundation for understanding the ecological history of seabirds in Svalbard in Holocene. [ABSTRACT FROM AUTHOR]

Many animals that possess a gizzard swallow stones or sandy grit, supposedly to aid in the mechanical breakdown of food. While this has been well documented in the literature, our study is the first to report the presence of stones in the gizzard of king penguin chicks. We found stones, so called ‘gastroliths’, in the pyloric region of the gizzard, the part of the digestive tract that is specialised for the mechanical breakdown of food. Stones were already present in the gizzard of chicks and, hence, during the first year of the life of king penguins, which is spent on land. Some chicks were found to have more than 130 stones (0.5–22 mm in size) in their gizzard. The gastroliths we found in king penguins are of the same geological origin as rocks present at the colony, which suggests that birds swallowed them there. The functional role of gastroliths in penguin chicks and adults is still unknown. We discuss the potential roles that these gastroliths might play in king penguins (i.e. aid in digestion, buoyancy control during foraging at sea, adaptation to fasting). [ABSTRACT FROM AUTHOR]

The striated caracara is a rare and specialised raptor, with a distribution restricted to outer islands of southern South America and the Falklands, where it lives in a unique obligate association with seabirds and seals. Despite its tameness, interesting adaptations and the fact that it is classified as near-threatened, there is virtually no published quantitative information on its demography, ecology and behaviour. We carried out a study on New Island, West Falklands, where the species was eradicated due to heavy persecution up to the 1960s. Recolonisation started after 1972 and presently there are an estimated 85 adult territorial pairs plus ca. 130 non-territorial immatures, representing an overall density of 15.5 striated caracaras per km2. The population is estimated to have increased by 15% per year over the past 3 decades, with the result that New Island now harbours the largest known breeding aggregation on a single island in the entire breeding range of the species. The spring and summer diet of striated caracaras on New Island is dominated by one small seabird, the thin-billed prion Pachyptila belcheri. An estimated 25,000 adult and sub-adult prions are consumed every year, but this possibly represents less than 1% of the local population. The diet of different pairs displayed significant differences, which were probably related to differences in the availability of prey types between territories. Breeding success in recent years was very high, suggesting that conditions are good and the population may not yet have reached the island’s carrying capacity. [ABSTRACT FROM AUTHOR]

Time-depth recorders are commonly deployed on diving animals to obtain information on their aquatic behaviour. The recorded data provide a 2D profile of diving activity. As analyses of diving behaviour from such profiles have become more complex, these analyses have often suffered from a lack of consistency and rigour. There is a growing need for a simple, comparative method to classify diving behaviour thoroughly and quantitatively. Here, a new approach to the classification of the dive profiles of penguins is described, which probably has applicability for many other diving predators as well. This simple approach uses a small, coherent set of criteria to classify behaviours in a detailed and quantified manner, and with relative objectivity. Classification of diving behaviour is possible from the temporal scale of a wiggle within a dive to the scale of a bout of dives. The new method will make comparisons between species easier and clearer because these comparisons will be undertaken within a consistent, more objective framework. [ABSTRACT FROM AUTHOR]