| genetic variation of southern hemisphere fur seals (arctocephalus spp.): investigation of population structure and species identity. | we have examined phylogenetic and geographic patterns of variation in the mitochondrial cytochrome b gene of southern hemisphere fur seals (arctocephalus spp.). our survey of 106 individuals from four putative species reveals three distinct patterns of variation reflecting ancient, recent historic, and contemporary gene flow. for the combined samples of subantarctic (arctocephalus tropicalis) and antarctic (arctocephalus gazella) fur seals, we find low levels of sequence diversity and reciprocal ... | 1997 | 9183848 |
| molecular characterization of mycobacteria isolated from seals. | tuberculosis (tb) was diagnosed in 10 seals from three species (arctocephalus australis, arctocephalus tropicalis and otaria flavescens) found in south america. the mycobacteria isolated from these cases belonged to the mycobacterium tuberculosis complex, as determined by rflp using an is6110 probe, spoligotyping, analysis of the 16s rrna gene sequence and by pcr-restriction analysis of hsp65. polymorphisms in gyra, katg, oxyr and pnca were investigated in some of the isolates, as well as the pr ... | 1999 | 10517604 |
| tuberculosis in a wild subantarctic fur seal from argentina. | the first case of tuberculosis is described in a wild subantarctic fur seal (arctocephalus tropicalis) found on the argentine coast. there was hydrothorax and white firm granulomatous lesions of 40-50 mm in diameter in the lungs. lesions consisted of a central area of caseous necrosis, an intermediate zone of epithelioid and lymphocytic mononuclear cells, and a peripheral zone of connective tissue. biochemical and drug sensitivity tests and inoculation of guinea pigs confirmed the identification ... | 1999 | 10574544 |
| response of wild subantarctic fur seal (arctocephalus tropicalis) females to ketamine and tiletamine-zolazepam anesthesia. | this study is the first to compare the anesthetic effects of two cyclohexamines on free-ranging subantarctic fur seal (arctocephalus tropicalis) females. from april to july 1999, 107 females were immobilized for tooth extraction and blood sampling, using either ketamine (ketalar, n = 58) alone or tiletamine-zolazepam (zoletil 100, n = 49) mixture. animals were injected intramuscularly at mean doses of 2.1 mg/kg for ketamine and 1.1 mg/kg for tiletamine-zolazepam mixture. individual response to b ... | 2002 | 12528456 |
| mass mortality of adult male subantarctic fur seals: are alien mice the culprits? | background: mass mortalities of marine mammals due to infectious agents are increasingly reported. however, in contrast to previous die-offs, which were indiscriminate with respect to sex and age, here we report a land-based mass mortality of subantarctic fur seals with apparent exclusivity to adult males. an infectious agent with a male-predilection is the most plausible explanation for this die-off. although pathogens with gender-biased transmission and pathologies are unusual, rodents are kno ... | 2008 | 19018284 |
| antimicrobial resistance and virulence factor gene profiles of enterococcus spp. isolates from wild arctocephalus australis (south american fur seal) and arctocephalus tropicalis (subantarctic fur seal). | enterococci are natural inhabitants of the gastrointestinal tracts in humans and animals. epidemiological data suggest that enterococci are important reservoirs of antimicrobial resistant genes that may be transmitted from other bacterial species the aim of this study was to investigate the species composition, antimicrobial resistance and virulence genes in enterococci recovered from fecal samples of wild arctocephalus australis and a. tropicalis found dead along the south coast of brazil. from ... | 2015 | 26347323 |
| enterococcus species diversity in fecal samples of wild marine species as determined by real-time pcr. | analyses using culture-independent molecular techniques have improved our understanding of microbial composition. the aim of this work was to identify and quantify enterococci in fecal samples of wild marine species using real-time quantitative pcr. seven enterococcus species were examined in fecal dna of south american fur seals (arctocephalus australis), subantarctic fur seals (arctocephalus tropicalis), green turtles (chelonia mydas), magellanic penguins (spheniscus magellanicus), snowy-crown ... | 2017 | 27991828 |
| change in plasma cortisol and metabolites during the attendance period ashore in fasting lactating subantarctic fur seals. | lactating fur seals (arctocephalus tropicalis) alternate foraging trips at sea and pup attendance periods ashore. during the onshore nursing periods, lactating females do not have access to food and meet both their own metabolic requirements and milk production from their body reserve. blood and milk samples were collected from females captured soon after their arrival ashore from a foraging trip and before their departure. milk lipid but not milk protein content was positively related to the bo ... | 2004 | 15123189 |
| the comparative energetics and growth strategies of sympatric antarctic and subantarctic fur seal pups at iles crozet. | the period of maternal dependence is a time during which mammalian infants must optimise both their growth and the development of behavioural skills in order to successfully meet the demands of independent living. the rate and duration of maternal provisioning, post-weaning food availability and climatic conditions are all factors likely to influence the growth strategies of infants. while numerous studies have documented differences in growth strategies at high taxonomic levels, few have invest ... | 2003 | 14610034 |
| novel insights into pasteurellosis in captive pinnipeds. | pasteurella multocida is a heterogeneous bacterium, which has the capacity to cause disease in a wide range of host species and is also recognized as an important zoonotic pathogen. two sequential deaths in captive fur seals occurred at sea world, australia during december 2017. a fibrinosuppurative bronchopneumonia in a subantarctic fur seal (arctocephalus tropicalis) resulted in death within 24 h of nonspecific signs of illness, whereas a septic peritonitis in a new zealand fur seal (arctoceph ... | 2019 | 30955815 |
| what's in a whisker? high-throughput analysis of twenty-eight c19 and c21 steroids in mammalian whiskers by ultra-performance convergence chromatography-tandem mass spectrometry. | obtaining longitudinal endocrinological data from free-ranging animals remains challenging. steroid hormones can be extracted sequentially from non-invasively sampled biologically inert keratinous tissues, such as feathers, nails, hair and whiskers. however, uncertainty regarding the type and levels of steroids incorporated into such tissues complicates their utility in wildlife studies. here, we developed a novel, comprehensive method to analyze fourteen c19 and fourteen c21 steroids deposited ... | 2020 | 32109749 |
| how does a fur seal mother recognize the voice of her pup? an experimental study of arctocephalus tropicalis. | in the subantarctic fur seal arctocephalus tropicalis, mothers leave their pups during the rearing period to make long and frequent feeding trips to sea. when a female returns from the ocean, she has to find her pup among several hundred others. taking into account both spectral and temporal domains, we investigated the individual vocal signature occurring in the 'female attraction call' used by pups to attract their mother. we calculated the intra- and inter-individual variability for each meas ... | 2002 | 11907050 |
| body composition changes, metabolic fuel use, and energy expenditure during extended fasting in subantarctic fur seal (arctocephalus tropicalis) pups at amsterdam island. | the fasting metabolism of 71- to 235-d-old subantarctic fur seal (arctocephalus tropicalis) pups from amsterdam island, southern indian ocean, was investigated during the long foraging trips of their mothers. body lipid reserves were proportionally greater in female than male pups and higher in postmoult (37%) than premoult (10%) animals. the mass-specific rate of mass loss did not differ between the sexes but was lower than observed in other species. daily mass loss was estimated to 56% fat, 10 ... | 2006 | 12794680 |
| a memory like a female fur seal: long-lasting recognition of pup's voice by mothers. | in colonial mammals like fur seals, mutual vocal recognition between mothers and their pup is of primary importance for breeding success. females alternate feeding sea-trips with suckling periods on land, and when coming back from the ocean, they have to vocally find their offspring among numerous similar-looking pups. young fur seals emit a 'mother-attraction call' that presents individual characteristics. in this paper, we review the perceptual process of pup's call recognition by subantarctic ... | 2004 | 15258632 |
| physiological response to extreme fasting in subantarctic fur seal (arctocephalus tropicalis) pups: metabolic rates, energy reserve utilization, and water fluxes. | surviving prolonged fasting requires various metabolic adaptations, such as energy and protein sparing, notably when animals are simultaneously engaged in energy-demanding processes such as growth. due to the intermittent pattern of maternal attendance, subantarctic fur seal pups have to repeatedly endure exceptionally long fasting episodes throughout the 10-mo rearing period while preparing for nutritional independence. their metabolic responses to natural prolonged fasting (33.4 +/- 3.3 days) ... | 2009 | 19776248 |
| selection for increased body length in subantarctic fur seals on amsterdam island. | the traditional distinction between ecological and evolutionary times is eroding, calling for tighter links between ecology and evolution. an example of such a brigde between the two disciplines is the so-called 'animal model', a methodology initially developed by animal breeders, which has become very popular among ecologists studying contemporary microevolution. using a bayesian multi-trait 'animal model', we investigated the quantitative genetics of body size, a fitness-related trait, in suba ... | 2011 | 21159006 |
| hormonal responses to extreme fasting in subantarctic fur seal (arctocephalus tropicalis) pups. | surviving prolonged fasting implies closely regulated alterations in fuel provisioning to meet metabolic requirements, while preserving homeostasis. little is known, however, of the endocrine regulations governing such metabolic adaptations in naturally fasting free-ranging animals. the hormonal responses to natural prolonged fasting and how they correlate to the metabolic adaptations observed, were investigated in subantarctic fur seal (arctocephalus tropicalis) pups, which, because of the inte ... | 2012 | 22319050 |
| deer mothers are sensitive to infant distress vocalizations of diverse mammalian species. | acoustic structure, behavioral context, and caregiver responses to infant distress vocalizations (cries) are similar across mammals, including humans. are these similarities enough for animals to respond to distress vocalizations of taxonomically and ecologically distant species? we show that mule deer (odocoileus hemionus) and white-tailed deer (odocoileus virginianus) mothers approach a speaker playing distress vocalizations of infant marmots (marmota flaviventris), seals (neophoca cinerea and ... | 2014 | 25226186 |
| foraging behavior of subantarctic fur seals supports efficiency of a marine reserve's design. | foraging behaviour of marine top predators is increasingly being used to identify areas of ecological importance. this is largely enabled by the ability of many such species to forage extensively in search of prey that is often concentrated in oceanographically productive areas. to identify important habitat in the southern indian ocean within and around south africa's prince edward islands' marine protected area (mpa), satellite transmitters were deployed on 12 lactating subantarctic fur seals ... | 2016 | 27163373 |
| determinants of individual foraging specialization in large marine vertebrates, the antarctic and subantarctic fur seals. | the degree of individual specialization in resource use differs widely among wild populations where individuals range from fully generalized to highly specialized. this interindividual variation has profound implications in many ecological and evolutionary processes. a recent review proposed four main ecological causes of individual specialization: interspecific and intraspecific competition, ecological opportunity and predation. using the isotopic signature of subsampled whiskers, we investigat ... | 2015 | 25649011 |
| milking strategy in subantarctic fur seals arctocephalus tropicalis breeding on amsterdam island: evidence from changes in milk composition. | milk composition was investigated throughout the 10-mo pup-rearing period in subantarctic fur seals (arctocephalus tropicalis) breeding on amsterdam island. the mean milk composition was 42.8% +/- 5.7% lipid, 12.1% +/- 1.5% protein, and 42.6% +/- 7.3% water. subantarctic fur seals breeding on amsterdam island produced one of the richest milks ever reported in otariids (20.4 +/- 2.9 kj/g), with lipid content contributing 85% of total gross energy. the high lipid levels measured in the milk of sub ... | 2006 | 11436139 |
| stable isotopes document seasonal changes in trophic niches and winter foraging individual specialization in diving predators from the southern ocean. | 1. climatic variation outside the breeding season affects fluctuations in population numbers of seabirds and marine mammals. a challenge in identifying the underlying biological mechanisms is the lack of information on their foraging strategies during winter, when individuals migrate far from their breeding grounds. 2. we investigated the temporal variability in resource partitioning within the guild of five sympatric subantarctic penguins and fur seals from crozet islands. the stable isotopic r ... | 2007 | 17584388 |
| long-term seasonal and interannual patterns of marine mammal strandings in subtropical western south atlantic. | understanding temporal patterns of marine mammal occurrence is useful for establishing conservation strategies. we used a 38 yr-long dataset spanning 1976 to 2013 to describe temporal patterns and trends in marine mammal strandings along a subtropical stretch of the east coast of south america. this region is influenced by a transitional zone between tropical and temperate waters and is considered an important fishing ground off brazil. generalized additive models were used to evaluate the tempo ... | 2016 | 26814667 |
| ménage à trois on macquarie island: hybridization among three species of fur seal (arctocephalus spp.) following historical population extinction. | human-induced changes to natural systems can cause major disturbances to fundamental ecological and population processes and result in local extinctions and secondary contacts between formerly isolated species. extensive fur seal harvesting during the nineteenth century on macquarie island (subantarctic) resulted in extinction of the original population. recolonization by three species has been slow and complex, characterized by the establishment of breeding groups of antarctic and subantarctic ... | 2006 | 17032266 |
| postsealing genetic variation and population structure of two species of fur seal (arctocephalus gazella and a. tropicalis). | commercial sealing in the 18th and 19th centuries had a major impact on the antarctic and subantarctic fur seal populations (arctocephalus gazella and a. tropicalis) in the southern ocean. the intensive and unrestricted nature of the industry ensured substantial reductions in population sizes and resulted in both species becoming locally extinct at some sites. however, both species are continuing to recover, through the recolonization of islands across their former range and increasing populatio ... | 2000 | 10736028 |
| characterization of the faecal bacterial community of wild young south american (arctocephalus australis) and subantarctic fur seals (arctocephalus tropicalis). | the microbiota of wild marine mammals is poorly understood, perhaps due to the migratory habits of some species and the difficulty in obtaining samples. using high-throughput sequencing, the present study examines the faecal bacterial community of wild young south american (arctocephalus australis) and subantarctic fur seals (a. tropicalis). faecal samples from south american (n = 6) and subantarctic fur seals (n = 4) found dead along the south coast of brazil were collected. sequences were assi ... | 2016 | 26880785 |
| metagenomic survey of viral diversity obtained from feces of subantarctic and south american fur seals. | the brazilian south coast seasonally hosts numerous marine species, observed particularly during winter months. some animals, including fur seals, are found dead or debilitated along the shore and may harbor potential pathogens within their microbiota. in the present study, a metagenomic approach was performed to evaluate the viral diversity in feces of fur seals found deceased along the coast of the state of rio grande do sul. the fecal virome of two fur seal species was characterized: the sout ... | 2016 | 26986573 |
| molecular detection of circovirus and adenovirus in feces of fur seals (arctocephalus spp.). | in some regions, little is known about exposure to viruses in coastal marine mammals. the present study aimed to detect viral rna or dna in 23 free-ranging fur seals on the northern coastline of rio grande do sul state, brazil. polymerase chain reaction was used to detect nucleic acids of circoviruses, adenoviruses, morbilliviruses, vesiviruses, and coronaviruses in the feces from twenty-one south american fur seals (arctocephalus australis) and two subantarctic fur seals (a. tropicalis). adenov ... | 2017 | 27803979 |
| phenotypic determinants of individual fitness in female fur seals: larger is better. | inter-individual differences in fitness in female vertebrates have often been related to phenotypic discrepancies, suggesting that bigger individuals exhibit greater fitness. however, the use of the temporally variable indices of quality, such as body mass/condition, may not represent the most reliable index over longer time intervals. few studies have assessed the direct influence of body size (bs) on individual fitness. we addressed this knowledge gap using data from long-term monitoring of in ... | 2007 | 17519194 |
| milk isotopic values demonstrate that nursing fur seal pups are a full trophic level higher than their mothers. | in mammals including humans, mother-to-offspring transfer of nutrients has been the focus of several isotopic studies. measurement of δ(13) c and δ(15) n values were mainly conducted on easily sampled tissues such as blood and hair that allow the calculation of apparent discrimination factors (∆(13) c and ∆(15) n) between offspring and maternal tissues. quantifying real ∆(13) c and ∆(15) n values requires the measurement of the δ(13) c and δ(15) n values of milk, the exclusive food of newborns. ... | 2015 | 26212163 |
| a baseline study of perfluorochemicals in franciscana dolphin and subantarctic fur seal from coastal waters of southern brazil. | | 2008 | 18295806 |
| preferred, small-scale foraging areas of two southern ocean fur seal species are not determined by habitat characteristics. | to understand and predict the distribution of foragers, it is crucial to identify the factors that affect individual movement decisions at different scales. individuals are expected to adjust their foraging movements to the hierarchical spatial distribution of resources. at a small local scale, spatial segregation in foraging habitat happens among individuals of closely situated colonies. if foraging segregation is due to differences in distribution of resources, we would expect segregated forag ... | 2019 | 31510989 |
| toxoplasmosis and sarcocystis spp. infection in wild pinnipeds of the brazilian coast. | the protozoans toxoplasma gondii and sarcocystis spp. (sarcocystidae: apicomplexa) affect a wide variety of vertebrates. both have been reported to infect pinnipeds, with impacts on health ranging from inapparent to fulminant disease and death. however, little is known regarding their infections and associated pathology in south american pinnipeds. we used histological techniques to survey for the presence of t. gondii and sarcocystis spp. in 51 stranded pinnipeds from brazil. immunohistochemica ... | 2019 | 31724556 |
| fatal pulmonary parafilaroidiasis in a free-ranging subantarctic fur seal (arctocephalus tropicalis) coinfected with two gammaherpesviruses and sarcocystis sp. | a juvenile subantarctic fur seal (arctocephalus tropicalis) found dead in santa catarina state, southern brazil, presented with disseminated verminous pneumonia due to parafilaroides sp. a concomitant infection with two different gammaherpesviruses was identified by pcr in different tissues; one of them possibly a novel species (tentatively named otariid herpesvirus 7). sarcocystis sp. dna was identified molecularly in skeletal muscle samples with intrasarcoplasmic bradyzoites and no apparent ti ... | 2019 | 31365717 |