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Papillomaviruses (family Papillomaviridae) are non-enveloped, circular, double-stranded DNA viruses known to infect squamous and mucosal epithelial cells. In the family Papillomaviridae there are 53 genera and 133 viral species whose members infect a variety of mammalian, avian, reptilian, and fish species. Within the Antarctic context, papillomaviruses (PVs) have been identified in Adélie penguins (Pygoscelis adeliae, 2 PVs), Weddell seals (Leptonychotes weddellii, 7 PVs), and emerald notothen (Trematomus bernacchii, 1 PV) in McMurdo Sound and Ross Island in eastern Antarctica. Here we identified 13 diverse PVs from buccal swabs of Antarctic fur seals (Arctocephalus gazella, 2 PVs) and leopard seal (Hydrurga leptonyx, 3 PVs) in western Antarctica (Antarctic Peninsula), and vaginal and nasal swabs of Weddell seals (8 PVs) in McMurdo Sound. These PV genomes group into four genera representing 11 new papillomavirus types, of which five are from two Antarctic fur seals and a leopard seal and six from Weddell seals. • 2 papillomaviruses identified in two individual Antarctic fur seals. • 3 papillomaviruses identified in a Leopard seal. • 8 papillomaviruses identified in virginal and nasal swabs of five Weddell seals. • 11 new papillomavirus types identified in 3 species of Antarctic pinnipeds. [ABSTRACT FROM AUTHOR]

Ornithogenic soils in Antarctica provide a biological archive of the occupation history and trophic ecology of penguins and other marine species over geological timescales. Hard prey remains and predator tissues, which are well preserved in ornithogenic soils, can act as paleoecological proxies of past environmental conditions. Here we examine ornithogenic soils from an active colony of Pygoscelis spp. penguins on Platter Island in the Danger Islands Archipelago along the northeastern side of the Antarctic Peninsula. We radiocarbon dated penguin tissues from excavated ornithogenic soils and parameterized an age-depth model of penguin occupation history. Hard prey remains were enumerated and recovered Pygoscelis spp. penguin and Antarctic fur seal (Arctocephalus gazella) tissues were analyzed for stable isotopes carbon (δ13C) and nitrogen (δ15N) analysis. The oldest recovered ornithogenic soils at Platter Island date to 502–653 years BP and coincide with the start of a period of increased warming and glacial discharge in the northeastern Antarctic Peninsula. Penguin tissues δ15N values increased between the oldest and youngest dated ornithogenic soils but seal tissues did not. This may indicate that the trophic level of penguins, but not seals, has increased over time, a hypothesis supported by the concurrent increase in the hard prey remains of fish and squid taxa common to penguin diets recovered from ornithogenic soils. Future studies of ornithogenic soils in the Danger Islands Archipelago are warranted to test this hypothesis and assess the potential confounding effects of varying ecosystem isotopic baselines and penguin species composition over time. [ABSTRACT FROM AUTHOR]

Assessing the trophic ecology of fur seals is essential for defining their roles as a top predator in Antarctic marine ecosystems. To this end, we examined the diet of Antarctic fur seals, Arctocephalus gazella, in the South Shetlands. While previous studies have considered the diet of this species at this location in summer, to the best of our knowledge, this is the first study to report on the diet of this population in winter, thus adding essential information on the extent of seasonal variation. A total of 224 scats were collected in the winter 2004 ( n = 118) and summer 2004/2005 ( n = 106) on the coasts of Stranger Point, Isla 25 de Mayo/King George. For the total study period krill ( Euphausia superba) was the main prey taxon, followed by fish, cephalopods and penguins. During winter Pleuragramma antarcticum was dominant, while myctophids were almost absent. Conversely, in summer Electrona antarctica and Gymnoscopelus nicholsi, followed by P. antarcticum, dominated the fish diet. It is concluded that fur seals centred their foraging activity on a krill community and fish associated with krill aggregations. [ABSTRACT FROM AUTHOR]

In otariids, mother’s recognition by pups is essential to their survival since females nurse exclusively their own young and can be very aggressive towards non-kin. Antarctic fur seal, Arctocephalus gazella, come ashore to breed and form dense colonies. During the 4-month lactation period, females alternate foraging trips at sea with suckling period ashore. On each return to the colony, females and pups first use vocalizations to find each other among several hundred conspecifics and olfaction is used as a final check. Such vocal identification has to be highly efficient. In this present study, we investigated the components of the individual vocal signature used by pups to identify their mothers by performing playback experiments on pups with synthetic signals. We thus tested the efficiency of this individual vocal signature by performing propagation tests and by testing pups at different playback distances. Pups use both amplitude and frequency modulations to identify their mother’s voice, as well as the energy spectrum. Propagation tests showed that frequency modulations propagated reliably up to 64m, whereas amplitude modulations and spectral content greatly were highly degraded for distances over 8m. Playback on pups at different distances suggested that the individual identification is a two-step process: at long range, pups identified first the frequency modulation pattern of their mother’s calls, and other components of the vocal signature at closer range. The individual vocal recognition system developed by Antarctic fur seals is well adapted to face the main constraint of finding kin in a crowd. [ABSTRACT FROM AUTHOR]

The Antarctic fur seal, Arctocephalus gazella, has a wide distribution range and breeds primarily in subantarctic and Antarctic locations of the Southern Ocean. We report the first record of this species in northern Chile in August, 2014. Although no external trauma was observed, the seal was presumed to be sick because it appeared to be underweight. This sighting is the northernmost record of this species on islands and the continental coastal areas of the southeastern South Pacific. [ABSTRACT FROM AUTHOR]

Molecular genetic studies of stools were performed to assess the spread of some clinically relevant antimicrobial resistance determinants (ARD) in a gentoo penguin (Pygoscelis papua) and an Antarctic fur seal (Arctocephalus gazella) on Livingston Island. Glycopeptide resistance genes (vanA / vanD and vanB) were detected in both fecal samples, while the penguin's one was also mecA -positive and bla NDM -positive. Because of the remoteness and the isolation of the sampling locations, the carriage of vancomycin-resistant Enterococcus spp., methicillin-resistant Staphylococcus aureus , and NDM-producing Enterobacterales or other gram-negative bacilli suggested an ocean pollution with antibiotic resistant bacteria (ARB). Additionally, due to the type of ARD we detected, our results are alarming, and they cannot be explained only with agricultural and/or aquacultural pollution. Even though the current study is a preliminary one, it also demonstrates the potential of the field genetics analyses carried out with minimal equipment as a reliable monitoring tool for pollution with ARB. • Gentoo penguin and Antarctic fur seal fecal samples were used for DNA extraction. • DNA was screened by PCR for the presence of antimicrobial resistance determinants (ARD). • Presence of ARD indicated resistance to some clinically significant antibiotics. [ABSTRACT FROM AUTHOR]

Antarctic fur seals ( Arctocephalus gazella) are major secondary consumers in the Southern Ocean, placing them in potential competition with commercial fisheries and requiring research to understand their seasonal habitat use. Using the data obtained during 14 shipboard surveys sampled on a fixed grid (150 K km) during mid- to late summer, I quantified the spatial distribution and intra-seasonal variability of fur seal sightings relative to distance to land and hydrographic boundaries. I test the hypothesis that fur seals display an increase in their at-sea abundance during mid- to late summer near the Antarctic Peninsula as they prepare to take up wintering grounds. I also test whether abundances of their potential prey, krill and myctophids, exhibit intra-seasonal variability. During midsummer, high-abundance areas are located near major breeding colonies; however, during late summer, there is an order-of-magnitude increase in fur seal abundance, coinciding with an increase in the number of high-abundance areas located in Bransfield Strait. Coincidently, abundance of Euphausia superba decreased and the myctophid Electrona antarctica increased between mid- and late-summer surveys. High-abundance areas of fur seals are not associated with the southern Antarctic Circumpolar Current front but are concentrated within 100 km from land, potentially indicating the location of haul out and important coastal habitat use areas. The dynamic increase in the number and location of high-abundance areas during late summer represents a considerable amount of mammalian predators entering the Antarctic Peninsula marine ecosystem. This information is important for understanding the seasonal impact of fur seals on regional marine food webs and their potential interaction with the autumn-winter krill fishery. [ABSTRACT FROM AUTHOR]

Abstract: The presence of Toxoplasma gondii antibodies was investigated in Antarctic marine mammals. Two hundred and eleven sera from different species of pinnipeds collected in years 2007, 2010 and 2011 from different locations in the South Shetland Islands and Antarctic Peninsula were analysed using a commercially available agglutination test kit. The presence of antibodies (titres≥1:25) against T. gondii was detected in a total of 28 animals (13.3%). Amongst animal species, percentages of detection were higher in Southern elephant seals (Mirounga leonina) (76.9%; 10/13) followed by Weddell seals (Leptonychotes weddellii) (41.9%; 13/31). Antibodies were also found in 4 of 165 (2.4%) Antarctic fur seals (Arctocephalus gazella) and 1 of 2 Crabeater seals (Lobodon carcinophaga). Highest titres (1:100–1:800) were also observed in Southern elephant seals and Weddell seals. To the best of our knowledge this is the first report on the detection of antibodies against T. gondii in Antarctic marine mammals. [Copyright &y& Elsevier]

The article presents a study on the ecosystem relationships between sea ice and prey abundance like krill density, and predator behavior. The study used a Bayesian hierarchical model (BHM) to link Antarctic fur seals and pups and utilized the collected data on Antarctic fur seals in Seal Island, Antarctica. Results showed that increased sea ice was associated to increased krill density while no relationship was found between maternal mass and foraging behavior of fur seals on pup growth rates.

Abstract: Genetic analyses can reliably determine the relationships among putative cases of twins in pinniped species. These studies demonstrate that field observations of nursing twins may often be cases of adoption or foster nursing of unrelated pups. A recent study of Antarctic fur seals (Arctocephalus gazella) on South Georgia Island found that only 3 of 11 putative twin cases were truly twins. Here we report results of genetic testing of eight putative cases of twinning (twin siblings and mother) observed at Cape Shirreff (62°27′30″S, 60°47′17″W), Livingston Island, Antarctica. Parentage and relatedness analyses using 18 microsatellite markers confirmed six out of the eight cases as twins and two cases of adoption/foster nursing of unrelated pups. All twins analyzed were dizygotic and in five out of six cases, the twins were likely full siblings (relatedness coefficient, or r xy μ=0.46, σ2 =0.004). In one case, the twins were likely half-siblings (r xy =0.17), supporting a previous finding of heteropaternity in Antarctic fur seals. This result suggests that mate infidelity during estrus maybe common in Antarctic fur seals, which has implications for our understanding of this species''s mating system. The twinning rate estimated at Cape Shirreff (0.12% or 6 twins per 4,965 births) is consistent with the scarcity of twin births observed in pinnipeds, which is associated with the high cost of nursing multiple pups in these animals. [Copyright &y& Elsevier]

Abstract: The use of intrinsic biomarkers to infer the foraging ecology of marine predators has become a common alternative to traditional methods of estimating diets and foraging behavior. In this study we examined the ability of the stable isotope analysis (δ15N and δ13C) of milk to infer seasonal variations in the diets and foraging habitats of female Antarctic fur seals (Arctocephalus gazella) breeding at Cape Shirreff, Livingston Island, Antarctica. We found that the stable nitrogen values of lipid-free milk were correlated with seasonal changes in female diet composition during the lactation period identified from scat collections. While we could not fully quantifying female diets using isotopic analysis, evidence from both scat collections and stable isotope analysis suggest that Antarctic krill (Euphausia superba) remained a major dietary item throughout lactation. In addition, these two methods independently highlighted the increasing importance of fish and squid in the diets of females as the season progresses. Furthermore, the isotopic values of milk collected during the perinatal fast suggest that females may be foraging in high productivity areas north of the South Shetland Islands and consume a larger proportion of fish and/or squid prior to parturition. While more confirmatory studies are needed to refine these methods, our results suggests that the δ15N and δ13C values of lipid-free milk can be used as a proxy to describe the foraging ecology of female Antarctic fur seals prior to and across the lactation period. [ABSTRACT FROM AUTHOR]

Foragers show adaptive responses to changes within their environment, and such behavioural plasticity can be a significant driving force in speciation. We investigated how lactating Antarctic fur seals, Arctocephalus gazella, adapt their foraging within two contrasting ecosystems. Location and diving data were collected concurrently, between December 2003 and February 2004, from 43 seals at Bird Island, where krill, Euphausia superba, are the main prey, and 39 at Heard Island, where mostly fish are consumed. Seals at Heard Island were shorter and lighter than those at Bird Island and they spent longer at sea, dived more frequently and spent more time in the bottom phase of dives. Generalized additive mixed effects models showed that diving behaviours differed between the islands. Both populations exploited diel vertically migrating prey species but, on average, Heard Island seals dived deeper and exceeded their estimated aerobic dive limits. We propose that the recovery of the Heard Island population may be limited by the relative inaccessibility and scarcity of food, whereas at Bird Island, the presence of abundant krill resources helps sustain extremely high numbers of seals, even with increased intra- and inter-specific competition. Both populations of fur seals appear to be constrained by their physiological limits, in terms of their optimal diving behaviour. However, there does appear to be some flexibility in strategy at the level of trip with animals adjusting their time at sea and foraging effort, in order to maximize the rate of delivery of energy to their pups. [ABSTRACT FROM AUTHOR]

The study of scats of adult male Antarctic fur seals Arctocephalus gazella (AFS) revealed occasional frequent capture of penguins. Although AFS adult males have been occasionally reported to kill king penguins Aptenodytes patagonicus at the shore, here we report the first observations of at-sea predation by AFS on adult king penguins in the Crozet archipelago, southern Indian Ocean. During our 20 days survey, we observed 17 penguins attacked and either severely injured or killed and consumed. Only AFS adult males were seen catching king penguins successfully. Some adult females and sub-adults also attempted to catch penguins, either at sea or in land, and so did subantarctic fur seals Arctocephalus tropicalis individuals. Our results confirm the ability of fur seals to catch and predate large seabirds, even at sea. [ABSTRACT FROM AUTHOR]

We investigated the variation of Antarctic fur seal ( Arctocephalus gazella) pup growth rates in response to sex, breeding season and duration of both maternal foraging trip and attendance bouts. Data were collected during five consecutive rearing seasons at Cape Shirreff, the most important breeding colony in the South Shetland Islands, Antarctica. Our results showed significant interannual and sexual variations in pup growth rates. Male pups grew significantly faster than female pups during 2000, 2001, 2002 and 2004 seasons, whilst during 2003 no difference was found. The interannual variation in pup growth rates was correlated with the interannual fluctuation in maternal foraging trip and attendance bouts. There was a significant effect of pup sex and maternal foraging trip duration on pup growth rates, which varied between years having foraging trip duration a major effect during 2003, when females spent more time at sea and interestingly on that year there were no sexual differences in pup growth rates. The effect of attendance bout on pup growth rates was not significant. Diet analysis showed that Antarctic krill ( Euphausia superba) was the most frequent prey item during the study period. Analysis of krill size distribution showed a significant difference in krill length, during 2003, when A. gazella preyed upon the smallest sizes of krill. In this study, sex was the most important factor on pup growth rates, but when prey availability seemed more limited, there are longer foraging trips and shorter attendance bouts the sex factor became less significant. [ABSTRACT FROM AUTHOR]

We document five cases of unusual colouration in Antarctic fur seals, Arctocephalus gazella, at Cape Shirreff, Livingston Island, from 1991–1992 to 2005–2006 austral summer seasons. This is the first time that these colour patterns have been reported for this species. These included four rare light coloured animals and one piebald individual. The incidence of this atypical colouring was low and the lack of resightings in previous and subsequent seasons suggests that these morphs are not common in Antarctic fur seals. Although the causes of these atypical light colour patterns are uncertain the subject is interesting for study and more observations on these atypical colourations are required for a proper assessment of the ecological and physiological implications of this condition in otariids can be conducted in the future. [ABSTRACT FROM AUTHOR]

The diet of non-breeding male Antarctic fur seals, Arctocephalus gazella, was investigated at Stranger Point, King George Island, through the analysis of scats during three consecutive summer seasons (1996, 1997, 1998). Overall, fish and krill were the most frequent prey occurring, respectively, in an average of 82.9% and 78.8% of samples ( n = 131), followed by penguins (22.8%) and cephalopods (17.8%). Myctophids constituted almost 90% of the fish predated, with Electrona antarctica and Gymnoscopelus nicholsi being the most abundant and frequent species consumed. All fish taxa identified were krill feeding species suggesting that seals foraged mainly on a krill and a fish community associated with krill aggregations. However, a seasonal change was observed in the relative proportions of the different prey taxa, with a progressive decrease with time in the occurrence of krill and a concomitant increase of fish, penguins and squid. Possible influence of the strong 1997/98 ENSO event is discussed. [ABSTRACT FROM AUTHOR]

This study examined the recovery process of an Antarctic fur-seal population, starting from minimal numbers after commercial exploitation to the now largest breeding population in the South Shetland Archipelago, Cape Shirreff and San Telmo Islets. It used direct census data from 20 breeding seasons (including 11 consecutive years) that spanned over 45 years. Since early population estimates, pup production increased at an intrinsic rate of ca. 20% which, during the last decade, dramatically slowed to 4.6%. The population-change trajectory is currently converging into a tightly bounded oscillation around an apparent equilibrium (carrying capacity), which is an order of magnitude lower than those levels before exploitation began. This pattern suggests the onset of an alternative stable state and highlights the far-reaching implications of strong and large-scale perturbations on marine systems. [ABSTRACT FROM AUTHOR]

Abstract: Natal philopatry is an important component of mammalian behaviour but is difficult to study in natural vertebrate populations due to the requirement for long-term individual-based spatial observations. Consequently, we quantified fine-scale patterns of natal philopatry in an intensively studied colony of Antarctic fur seals (Arctocephalus gazella), where a scaffold walkway allows individual locations to be measured to the nearest metre. Using subcutaneous PIT tags, we tracked the early life histories of 335 females born within the colony, of which 38 were resighted as breeding adults. We found that individual females returned to as little as one body length (2m) of their birth locations. Moreover, distances between natal and pupping sites were not correlated with female age, but instead tended to decrease with the number of seasons an individual was sighted ashore. This suggests that breeding experience may be a better predictor than age of the ability of females to occupy preferred sites within fur seal colonies. [Copyright &y& Elsevier]