Journal articles on the topic 'Australian fur seals'
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1
Shaughnessy, Peter D., Jane McKenzie, Melanie L. Lancaster, Simon D. Goldsworthy, and Terry E. Dennis. "Australian fur seals establish haulout sites and a breeding colony in South Australia." Australian Journal of Zoology 58, no. 2 (2010): 94. http://dx.doi.org/10.1071/zo10017.
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Australian fur seals (Arctocephalus pusillus doriferus) breed on Bass Strait islands in Victoria and Tasmania. They have been recorded in South Australia (SA) for many years as non-breeding visitors and on Kangaroo Island frequently since 1988, mostly in breeding colonies of the New Zealand fur seal (A. forsteri) which is the most numerous pinniped in SA. Australian fur seals have displaced New Zealand fur seals from sections of the Cape Gantheaume colony on Kangaroo Island. North Casuarina Island produced 29 Australian fur seal pups in February 2008. Australian fur seal pups were larger than New Zealand fur seal pups in the same colony and have been identified genetically using a 263-bp fragment of the mitochondrial DNA control region. North Casuarina Island has been an important breeding colony of New Zealand fur seals, but pup numbers there decreased since 1992–93 (contrary to trends in SA for New Zealand fur seals), while numbers of Australian fur seals there have increased. This study confirms that Australian fur seals breed in SA. The two fur seal species compete for space onshore at several sites. Australian fur seals may compete for food with endangered Australian sea lions (Neophoca cinerea) because both are bottom feeders.
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Shaughnessy, Peter D., Catherine M. Kemper, David Stemmer, and Jane McKenzie. "Records of vagrant fur seals (family Otariidae) in South Australia." Australian Mammalogy 36, no. 2 (2014): 154. http://dx.doi.org/10.1071/am13038.
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Two fur seal species breed on the southern coast of Australia: the Australian fur seal (Arctocephalus pusillus doriferus) and the New Zealand fur seal (A. forsteri). Two other species are vagrants: the subantarctic fur seal (A. tropicalis) and the Antarctic fur seal (A. gazella). We document records of vagrant fur seals in South Australia from 1982 to 2012 based primarily on records from the South Australian Museum. There were 86 subantarctic fur seals: 49 specimens and 37 sightings. Most (77%) were recorded from July to October and 83% of all records were juveniles. All but two specimens were collected between July and November. Sightings were prevalent during the same period, but there were also nine sightings during summer (December–February), several of healthy-looking adults. Notable concentrations were near Victor Harbor, on Kangaroo Island and Eyre Peninsula. Likely sources of subantarctic fur seals seen in South Australia are Macquarie and Amsterdam Islands in the South Indian Ocean, ~2700 km south-east and 5200 km west of SA, respectively. There were two sightings of Antarctic fur seals, both of adults, on Kangaroo Island at New Zealand fur seal breeding colonies. Records of this species for continental Australia and nearby islands are infrequent.
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Arnould, JPY, CL Littnan, and GM Lento. "First contemporary record of New Zealand fur seals Arctocephalus forsteri breeding in Bass Strait." Australian Mammalogy 22, no. 1 (2000): 57. http://dx.doi.org/10.1071/am00057.
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DURING the late eighteenth and early nineteenth centuries (1798 - 1825), large numbers of fur seals were hunted on the islands off southeastern Australia. It is estimated that >300,000 pelts were collected before hunting became commercially nonviable and the seals gained statutory protection in 1889 (Warneke and Shaughnessy 1985). Two types of fur seals were known to occur in southeastern Australian waters but cargo records from the sealing vessels active in the area do not accurately identify the species taken, referring to them only as ?black? and ?brown? seals (Goldsworthy et al. 1997). There are currently two species of fur seal found in these waters: the New Zealand fur seal (Arctocephalus forsteri) and the Australian fur seal (Arctocephalus pusillus doriferus). Based on pelage colour, it has been suggested that these species correspond to the ?black? and ?brown? species, respectively, referred to by the sealers (Goldsworthy et al. 1997).
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Dennis, T. E., and P. D. Shaughnessy. "Seal survey in the Great Australian Bight region of Western Australia." Wildlife Research 26, no. 3 (1999): 383. http://dx.doi.org/10.1071/wr98047.
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In December 1996, a survey by helicopter of the Baxter Cliffs region of the Great Australian Bight in Western Australia did not locate any previously unreported colonies of the Australian sea lion or New Zealand fur seal. Although geologically contiguous with the Bunda Cliffs in South Australia (where sea lions have a scattered distribution), the Baxter Cliffs appeared generally more weathered and stable, with fewer collapsed sections of cliff forming platforms and providing habitat for seals. In total, 29 Australian sea lions were observed during the survey. Most were at a previously surveyed site approximately 2 km west of Twilight Cove. Ten other sites were recorded as potentially providing haul- out opportunity for sea lions; they were mainly caves and deep overhangs with access from the sea. No fur seals were seen. From this survey and from other records, we estimate the Australian sea lion population along the Baxter Cliffs in the Great Australian Bight region of Western Australia at less than 100 animals.
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Ling, JK. "Impact Of Colonial Sealing On Seal Stocks Around Australia, New Zealand And Subantarctic Islands Between 150 And 170 Degrees East." Australian Mammalogy 24, no. 1 (2002): 117. http://dx.doi.org/10.1071/am02117.
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Details of southern elephant seal oil and fur seal and sea lion skin cargoes have been extracted from a large number of secondary sources dealing with Australian and New Zealand maritime history, which in turn referred to numerous primary sources of information. The data were collated and analysed for ten areas in the south-west Pacific region and published recently in two separate larger works. This review is a synthesis and analysis of the impact of the colonial sealing industry on seal stocks in the region, based on those papers, with some minor revisions and reference to works by other authors. Colonial sealing lasted from the late 18th to the mid- 19th century and was followed by sporadic hunting until the late 1940s. Southern elephant seals (Mirounga leonina) were hunted for their oil; and Australian fur seals (Arctocephalus pusillus doriferus), New Zealand fur seals (Arctocephalus forsteri), Australian sea lions (Neophoca cinerea) and New Zealand sea lions (Phocarctos hookeri) were targeted for their skins and some oil. At least 1,081 tons of elephant seal oil were shipped from King Is. between 1802 and 1819, while 8,380 tons were shipped from Macquarie Is. between 1810 and 1919. More than 1.4 million skins of both species of fur seals were harvested between 1792 and 1949, but only 4,000 Neophoca and 5,700 Phocarctos pelts are recorded as having been shipped by 1840. The Antipodes Islands yielded more than a quarter of the total fur seal skin harvest, and New Zealand and southern Australia each delivered a quarter of the total. Current numbers of the two species of fur seals combined are about a tenth of the crudely estimated size (1.5 million) of the original population. The exploited fur seals and sea lions were probably the same species as occur today at the original sealing localities, apart from Macquarie Is. where the identity of the exploited fur seals remains in doubt. There is some evidence that Maoris and Australian Aborigines hunted seals in pre-European times, resulting in reduced ranges and depleted stocks that were exploited later by colonial sealers.
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Gales, N. J., B. Haberley, and P. Collins. "Changes in the abundance of New Zealand fur seals, Arctocephalus forsteri, in Western Australia." Wildlife Research 27, no. 2 (2000): 165. http://dx.doi.org/10.1071/wr99027.
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New Zealand fur seals, Arctocephalus forsteri, have been increasing in abundance in South Australia for at least the past three decades. A survey of New Zealand fur seals during the 1989/90 breeding season determined that about 20% of the Australian population bred at 16 sites in Western Australia, amounting to 1429 pups and an absolute abundance estimate of 7100 fur seals. A further survey of all fur seal colonies in Western Australia to determine current pup production and abundance estimates, and trends in pup production since the previous survey was undertaken in January 1999. Of the 17 breeding sites now known in Western Australia, 16 were surveyed and pup production had increased at all but one. The rate of change in pup production at the one unsurveyed site (West Island), was estimated as being equivalent to the mean rate of change at other sites. The estimated mean annual, exponential rate of increase (r) for all sites was 0.09, equivalent to a 9.8% annual increase in pup production and an overall increase in pup production in Western Australia of 113.3% between surveys. Total annual pup production has increased to 3090. The estimate of absolute abundance of New Zealand fur seals in Western Australia is now 15 100, in contrast to the 7100 estimated for the 1989/90 season. Mortality of pups at the time of the survey was estimated to be at least 1.3%. It is predicted that New Zealand fur seal populations will continue to increase in Western Australia. This is likely to have important management implications regarding aquaculture and fisheries activities. The increase in fur seal populations appears to be in contrast to populations of Australian sea lions, Neophoca cinerea, for which preliminary data show no evidence for a population increase. It is unknown whether the dynamics affecting these two species are related.
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Brothers, N., and D. Pemberton. "Status of Australian and New-Zealand Fur Seals at Maatsuyker Island, Southwestern Tasmania." Wildlife Research 17, no. 6 (1990): 563. http://dx.doi.org/10.1071/wr9900563.
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Surveys were carried out between 1987 and 1989 on Maatsuyker I. and nearby Needle Rocks off southern Tasmania to establish the status and identification of the seals present. New Zealand fur seals, Arctocephalus forsteri, were found on Maatsuyker I. There were at least 15 pups born on the island in 1987/88. Australian fur seals, Arctocephalus pusillus doriferus, use the islands as a haulout site but do not breed here. The distribution of New Zealand fur seals can now be amended to include Tasmanian waters. Records discussed here also alter aspects of the status of Australian fur seals because the Maatsuyker group is not a breeding site for this species and breeding colonies are therefore restricted to Bass Strait waters.
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Kirkwood, Roger, David Pemberton, Rosemary Gales, Andrew J. Hoskins, Tony Mitchell, Peter D. Shaughnessy, and John P. Y. Arnould. "Continued population recovery by Australian fur seals." Marine and Freshwater Research 61, no. 6 (2010): 695. http://dx.doi.org/10.1071/mf09213.
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Australian fur seals (Arctocephalus pusillus doriferus) are conspicuous, top-level predators in coastal waters of south-eastern Australia that were over-harvested during the 1800s and have had a delayed recovery. A previous species-wide estimate of live pups in 2002 recorded a near-doubling of annual pup production and a 5% annual growth rate since the 1980s. To determine if pup production increased after 2002, we estimated live pup numbers in 2007. Pups were recorded at 20 locations: 10 previously known colonies, three newly recognised colonies and seven haul-out sites where pups are occasionally born. Two colonies adjacent to the Victorian coast accounted for 51% of live pups estimated: Seal Rocks (5660 pups, 25.9%) and Lady Julia Percy Island (5574 pups, 25.5%). Although some colonies were up and some were down in pup numbers, the 2007 total of 21 882 ± 187 (s.e.) live pups did not differ significantly from a recalculated estimate of 21 545 ± 184 in 2002, suggesting little change to overall population size. However, the colonisation of three new sites between 2002 and 2007 indicates population recovery has continued.
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Lento, Gina M., Robert H. Mattlin, Geoffrey K. Chambers, and C. Scott Baker. "Geographic distribution of mitochondrial cytochrome b DNA haplotypes in New Zealand fur seals (Arctocephalus forsteri)." Canadian Journal of Zoology 72, no. 2 (February 1, 1994): 293–99. http://dx.doi.org/10.1139/z94-040.
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Nucleotides spanning 361 base pairs of the 5′ portion of the mitochondrial cytochrome b gene were sequenced from 16 New Zealand fur seals, Arctocephalus forsteri, representing seven rookeries in three different regions: the east and west coasts of New Zealand, and Western Australia. Five different mitochondrial haplotypes were observed in these novel sequence data for this species. The geographical distribution of the cytochrome b haplotypes was shown to be heterogeneous by three statistical tests. The major finding of this study is the difference between haplotypes found in fur seals from Western Australian rookeries and haplotypes found in fur seals from New Zealand rookeries. The nucleotide sequence difference found in pairwise comparisons among the surveyed individuals is in the range 0.3–0.8%. One individual showed an unexpectedly large sequence divergence (range 3.3–4.2%) from all other fur seals in this study. We compare alternative hypotheses that this individual is a descendant of an ancient maternal lineage which survived a population bottleneck, that New Zealand fur seals exhibit a rather large amount of genetic variability at this locus, or that this particular individual is a hybrid. Western Australian rookeries were extirpated as a result of sealing during the early 1800s. The geographic distribution of mitochondrial cytochrome b haplotypes suggests that the extirpated Australian rookeries were not recolonized by migrants from New Zealand. No genetic division between fur seal populations sampled from the east and west coasts of New Zealand is revealed using this region of the mitochondrial genome as a genetic marker, but we suggest that it should be possible to create a more discriminating test by examining a more variable DNA target such as the mitochondrial control region.
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Kirkwood, Roger, and John P. Y. Arnould. "Foraging trip strategies and habitat use during late pup rearing by lactating Australian fur seals." Australian Journal of Zoology 59, no. 4 (2011): 216. http://dx.doi.org/10.1071/zo11080.
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Australian fur seals (Arctocephalus pusillus doriferus) are the most conspicuous and abundant marine mammal in shelf waters of south-eastern Australia. To successfully rear offspring, the females must encounter sufficient prey on each foraging trip out of a central place for periods up to11 months each year. We investigated foraging trip strategies and habitat use by the females in three winter–spring periods, 2001–03, from four colonies that span the species’ latitudinal range and contribute 80% of pup production. Trip durations of 37 females averaged 6.1 ± 0.5 (s.e.) days, although >90% of the seal’s time at sea was spent <150 km travel (<2 days) away. Most females exhibited strong fidelities to individually preferred hot-spots. Females from colonies adjacent to productive shelf-edge waters generally had shorter trips, had smaller ranges, foraged closer to colonies and exhibited less diversity in trip strategies than did those from colonies more distant from a shelf-edge. From a management perspective, there was minimal overlap (<1%) between where females foraged and a system of marine reserves established in 2007, suggesting that habitats visited by lactating Australian fur seals currently receive minimal legislative protection.
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Pemberton, David, and Rosemary Gales. "Australian fur seals (Arctocephalus pusillus doriferus) breeding in Tasmania: population size and status." Wildlife Research 31, no. 3 (2004): 301. http://dx.doi.org/10.1071/wr02083.
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This study confirms the persistence of five major breeding colonies of Australian fur seals (Arctocephalus pusillus doriferus) in Tasmanian Bass Strait waters. Incidental births also occasionally occur in very low numbers at other sites. Data collected between 1989 and 1999 shows that estimates of the minimum number of pups born at the major colonies varies considerably between sites and years. No colony has shown a consistent trend in pup production over the last 11 seasons. The most recent count for all Tasmanian colonies for the 1999 breeding season provided a minimum estimate of 3254 pups produced, similar to the estimate of 3373 in 1989. The highest estimate was recorded in 1995 when at least 6024 pups were born. Combining the most recent counts with the numbers estimated for the four Victorian colonies (13 872) gives a minimum pup production of 17 126 for the species, with only one-fifth of all pups being born on Tasmanian islands. Application of population estimators to translate pup numbers to population size for the species results in a conservative estimate of 68 500 individuals with upper and lower bounds of 60 000 and 77 000 Australian fur seals. Numbers of Australian fur seals remain low relative to other fur seal populations, with Australian fur seals being less numerous by an order of magnitude compared with their South African counterpart (A. p. pusillus). The current estimate of the total population of Australian fur seals is approximately half that of pre-sealing levels. The current number of breeding colonies in Tasmania indicates that the population of Australian fur seals breeding in Tasmanian waters has stabilised at well below their historic pre-sealing levels, with at least four sites remaining vacant. The species remains vulnerable due to its small population size, with Tasmanian breeding colonies being particularly vulnerable because of low numbers and due to the profound influence of weather events on pup survival.
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Kirkwood, Roger, Michael Lynch, Nick Gales, Peter Dann, and Michael Sumner. "At-sea movements and habitat use of adult male Australian fur seals (Arctocephalus pusillus doriferus)." Canadian Journal of Zoology 84, no. 12 (December 2006): 1781–88. http://dx.doi.org/10.1139/z06-164.
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Foraging by adult male otariids, a demographic component that often interacts with commercial fisheries, are poorly known. To assess movement patterns and habitat use, nine adult male Australian fur seals ( Arctocephalus pusillus doriferus Wood Jones, 1925) from Seal Rocks, in northern Bass Strait, southeastern Australia, were tracked for periods ranging from 66 to 223 d during 1999–2001. Mean ± SD at-sea and on-land durations were 6.9 ± 2.1 d (range 2.3–10.3 d, n = 9 seals) and 2.4 ± 0.9 d (range 0.8–4.1 d), respectively. All seals foraged almost exclusively in continental shelf waters and mostly (65%–97% of time at sea) in water columns that were between 40 and 100 m deep. Six of nine seals tracked for >30 d spent 64%–98% of their time-at-sea foraging at distances <200 km from Seal Rocks, although the maximum distance achieved from the colony was 1208 km. The seals’ foraging ranges overlapped with the ranges of operation of virtually all fin-fish fisheries in southeastern Australia, but fisheries overlap was low in the most frequented foraging area of central-western Bass Strait.
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Stamation, K. A., P. D. Shaughnessy, and A. J. Constable. "Status of Australian Fur Seals, Arctocephalus Pusillus doriferus (Carnivora: Otariidae) At Cape Bridgewater, Victoria." Australian Mammalogy 20, no. 1 (1998): 63. http://dx.doi.org/10.1071/am97063.
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Australian fur seals Arctocephalus pusillus doriferus are well known at Cape Bridgewater (38° 23'S, 141° 25'E) in western Victoria. The colony consists of a rock platform at the base of a 50m cliff and two caves. Fur seals frequent nearby waters within 50 m of shore. Between 21 November 1995 and 22 June 1996, the maximum number of fur seals recorded was 640 and the minimum was 207. The number of fur seals visible from the observation points and inside one of two caves is dependent on sea conditions. Juveniles were the most abundant age-class. A single pup was recorded during the pupping season. This study confirms that Cape Bridgewater should be considered a non-breeding colony.
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Arnould, J. P. Y., D. M. Trinder, and C. P. McKinley. "Interactions between fur seals and a squid jig fishery in southern Australia." Marine and Freshwater Research 54, no. 8 (2003): 979. http://dx.doi.org/10.1071/mf03030.
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Interactions between Australian fur seals (Arctocephalus pusillus doriferus) and the Southern Squid Jig Fishery (SSJF) were investigated in April–May 2002. Details on the number of seals present, distance from the vessel, age and gender, and their behaviour were recorded using scan sampling techniques over 26 nights from eight vessels operating out of Portland and Port Fairy on the southwest coast of Victoria. Seals were observed on all nights but none were recorded in 30% of all (777) scan observations. Of the seals attending vessels at any one time (1.89 ± 0.24), 67% were involved in activities unrelated to jigging operations with the most common behaviour category being resting/grooming. Only 3.6% of observations involved seals targeting squid caught on jig lures whereas a further 29% were of foraging on squid within 40 m of the vessel. Damage to fishing gear attributable to seals was recorded on only three occasions. There was no evidence of negative impacts on seals from vessel operations. The majority of seals foraging on squid around vessels were adult females (71%) with the remainder being almost exclusively juvenile males. The current level of interactions between Australian fur seals and vessels in the SSJF appears minor.
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Gibbens, J., and J. P. Y. Arnould. "Age-specific growth, survival, and population dynamics of female Australian fur seals." Canadian Journal of Zoology 87, no. 10 (October 2009): 902–11. http://dx.doi.org/10.1139/z09-080.
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Postsealing population recovery rates of fur seals and sea lions have differed markedly, perhaps owing to habitat type. Australian fur seals ( Arctocephalus pusillus doriferus Wood Jones, 1925) employ a benthic foraging mode similar to sea lions, and have exhibited similarly slow population recovery. Nonetheless, the population doubled in recent decades, suggesting a recent change in demographic rates. In the present study, the frequency and size of known-age females (n = 297) were used to create body growth and survivorship models. These were compared with models obtained in the 1970s before the recent population increase. Body growth, which is relatively rapid in comparison to other fur seal species, remains unchanged since the 1970s, suggesting that density-dependent effects are absent despite the population increases. Adult survival rates (weighted mean: 0.885) have increased greatly since the 1970s and are the likely mechanism of the recent increases. Total population abundance was estimated to be 4.5 times that of pups. Australian fur seals display high survivorship, rapid body growth, low fecundity, and low population growth rates; all are characteristics typical of benthic foraging sea lions rather than other fur seals.
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Shaughnessy, PD, NJ Gales, TE Dennis, and SD Goldsworthy. "Distribution and abundance of New Zealand fur seals, Arctocephalus forsteri, in South Australia and Western Australia." Wildlife Research 21, no. 6 (1994): 667. http://dx.doi.org/10.1071/wr9940667.
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A survey to determine the distribution and abundance of New Zealand fur seals, Arctocephalus forsteri, in South Australia and Western Australia was conducted in January-March 1990. Minor surveys were conducted in the summers of 1987-88, 1988-89 and 1990-91. Although the surveys were primarily of black pups in breeding colonies, opportunity was taken to count fur seals of all age-classes, including those in non-breeding colonies. Pups were counted and, in more accessible and larger colonies, numbers of pups were estimated by a mark-recapture technique. The latter technique gave higher estimates than counting, and was considered more accurate. In South Australia, the seals extend from The Pages in Backstairs Passage to Nuyts Reef in the Great Australian Bight. In Western Australia, the range comprised islands on the south coast from the Recherche Archipelago to islands near Cape Leeuwin. There are 29 breeding localities; 13 are in South Australia and 16 in Western Australia. Eighteen of these have not been reported previously. The term ''breeding locality'' is used for aggregations of breeding colonies as well as for isolated breeding colonies. Estimates of the number of pups for the 1989-90 breeding season were 5636 in South Australia and 1429 in Western Australia. This leads to a population estimate of approximately 34600 seals in these two states (using a multiplier of 4.9). But such estimates of overall abundance must be treated cautiously as the multiplier incorporates estimates of population parameters not available for A. forsteri. Most of the population (77%) is in central South Australian waters (from Kangaroo Island to the southern end of Eyre Peninsula). With the estimate of 100 for a breeding colony in southern Tasmania, the population of New Zealand fur seals in Australia can be estimated at 34700. Historical aspects of some colonies are outlined and evidence for increases described. The largest breeding localities are at South Neptune Islands (1964 pups) and North Neptune Islands (1472). The combined Neptunes group accounts for 49% of the pup estimate for Australia. One-fifth of the pups are from colonies on Kangaroo Island and the nearby Casuarinas.
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McLean, Lachlan J., Steve George, Daniel Ierodiaconou, Roger J. Kirkwood, and John P. Y. Arnould. "Impact of rising sea levels on Australian fur seals." PeerJ 6 (October 16, 2018): e5786. http://dx.doi.org/10.7717/peerj.5786.
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Global warming is leading to many unprecedented changes in the ocean-climate system. Sea levels are rising at an increasing rate and are amplifying the impact of storm surges along coastlines. As variability in the timing and strength of storm surges has been shown to affect pup mortality in the Australian fur seal (Arctocephalus pusillus doriferus), there is a need to identify the potential impacts of increased sea level and storm surges on the breeding areas of this important marine predator in Bass Strait, south-eastern Australia. Using high-resolution aerial photography and topographic data, the present study assessed the impacts of future inundation levels on both current and potential breeding habitats at each colony. Inundation from storm surges, based on a predicted rise in sea level, was modeled at each colony from 2012 to 2100. As sea level increases, progressively less severe storm surge conditions will be required to exceed current inundation levels and, thus, have the potential for greater impacts on pup mortality at Australian fur seal colonies. The results of the present study indicate that by 2100, a 1-in-10 year storm will inundate more habitat on average than a present-day 1-in-100 year storm. The study highlights the site-specific nature of storm surge impacts, and in particular the importance of local colony topography and surrounding bathymetry with small, low-lying colonies impacted the most. An increased severity of storm surges will result in either an increase in pup mortality rates associated with storm surges, or the dispersal of individuals to higher ground and/or new colonies.
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Lynch, Michael, Pádraig J. Duignan, Trevor Taylor, Ole Nielsen, Roger Kirkwood, John Gibbens, and John P. Y. Arnould. "EPIZOOTIOLOGY OF BRUCELLA INFECTION IN AUSTRALIAN FUR SEALS." Journal of Wildlife Diseases 47, no. 2 (April 2011): 352–63. http://dx.doi.org/10.7589/0090-3558-47.2.352.
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Shaughnessy, P. D. "New mammals recognised for Australia - Antarctic and Subantarctic Fur Seals Arctocephalus species." Australian Mammalogy 15, no. 1 (1992): 77. http://dx.doi.org/10.1071/am92010.
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Recent authoritative texts on Australian mammals include several pinniped species but most omit the Antarctic Fur Seal Arctocephalus gazella and Subantarctic Fur Seal A. tropicalis. The former species breeds at Heard Island; at Macquarie Island it breeds in territories with A. tropicalis. Information is tabulated on skulls of these two species held in Australian museums. It is argued that they should be included in comprehensive lists of Australian mammals.
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Ladds, Monique A., Marcus Salton, David P. Hocking, Rebecca R. McIntosh, Adam P. Thompson, David J. Slip, and Robert G. Harcourt. "Using accelerometers to develop time-energy budgets of wild fur seals from captive surrogates." PeerJ 6 (October 26, 2018): e5814. http://dx.doi.org/10.7717/peerj.5814.
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BackgroundAccurate time-energy budgets summarise an animal’s energy expenditure in a given environment, and are potentially a sensitive indicator of how an animal responds to changing resources. Deriving accurate time-energy budgets requires an estimate of time spent in different activities and of the energetic cost of that activity. Bio-loggers (e.g., accelerometers) may provide a solution for monitoring animals such as fur seals that make long-duration foraging trips. Using low resolution to record behaviour may aid in the transmission of data, negating the need to recover the device.MethodsThis study used controlled captive experiments and previous energetic research to derive time-energy budgets of juvenile Australian fur seals (Arctocephalus pusillus)equipped with tri-axial accelerometers. First, captive fur seals and sea lions were equipped with accelerometers recording at high (20 Hz) and low (1 Hz) resolutions, and their behaviour recorded. Using this data, machine learning models were trained to recognise four states—foraging, grooming, travelling and resting. Next, the energetic cost of each behaviour, as a function of location (land or water), season and digestive state (pre- or post-prandial) was estimated. Then, diving and movement data were collected from nine wild juvenile fur seals wearing accelerometers recording at high- and low- resolutions. Models developed from captive seals were applied to accelerometry data from wild juvenile Australian fur seals and, finally, their time-energy budgets were reconstructed.ResultsBehaviour classification models built with low resolution (1 Hz) data correctly classified captive seal behaviours with very high accuracy (up to 90%) and recorded without interruption. Therefore, time-energy budgets of wild fur seals were constructed with these data. The reconstructed time-energy budgets revealed that juvenile fur seals expended the same amount of energy as adults of similar species. No significant differences in daily energy expenditure (DEE) were found across sex or season (winter or summer), but fur seals rested more when their energy expenditure was expected to be higher. Juvenile fur seals used behavioural compensatory techniques to conserve energy during activities that were expected to have high energetic outputs (such as diving).DiscussionAs low resolution accelerometry (1 Hz) was able to classify behaviour with very high accuracy, future studies may be able to transmit more data at a lower rate, reducing the need for tag recovery. Reconstructed time-energy budgets demonstrated that juvenile fur seals appear to expend the same amount of energy as their adult counterparts. Through pairing estimates of energy expenditure with behaviour this study demonstrates the potential to understand how fur seals expend energy, and where and how behavioural compensations are made to retain constant energy expenditure over a short (dive) and long (season) period.
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Shaughnessy, P. D., S. D. Goldsworthy, and A. I. Mackay. "The long-nosed fur seal (Arctocephalus forsteri) in South Australia in 2013–14: abundance, status and trends." Australian Journal of Zoology 63, no. 2 (2015): 101. http://dx.doi.org/10.1071/zo14103.
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The long-nosed (or New Zealand) fur seal (Arctocephalus forsteri) breeds in southern Australia and New Zealand. Most of the Australian population is in South Australia, between Kangaroo Island and Eyre Peninsula. Fur seal populations in southern Australia were heavily exploited by colonial sealers between 1801 and 1830, resulting in major reductions. Numbers remained low for 150 years, then slowly built up and new colonies established across their presumed former range. Here we present estimates of pup abundance at South Australia colonies, mostly during the 2013–14 breeding season. Long-nosed fur seals bred from Baudin Rocks in the south-east to Fenelon Island in the north-west. In total, 29 breeding colonies produced 20 431 pups, 3.6 times greater than the 1989–90 estimate; the increase is attributed to recovery from 19th century overharvesting. The 2013–14 pup estimate leads to an estimate of abundance of long-nosed fur seals in South Australia of 97 200. Most pups were on Kangaroo Island (49.6%) and the Neptune Islands (38.6%). New breeding colonies were identified on Williams Island and at two small sites on Kangaroo Island. The increasing trend in South Australia is likely to continue over the coming decade, primarily by expansion in colonies on Kangaroo Island and by establishment of new colonies.
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Gales, R., D. Pemberton, CC Lu, and MR Clarke. "Cephalopod diet of the Australian fur seal: Variation due to location, season and sample type." Marine and Freshwater Research 44, no. 5 (1993): 657. http://dx.doi.org/10.1071/mf9930657.
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In Tasmanian waters, Arctocephalus pusillus doriferus preyed on 11 species of cephalopods, predominantly Nototodarus gouldi followed by Sepioteuthis australis and Sepia apama. Cephalopods were more important in the diet of the seals in Bass Strait than in southern Tasmanian waters. The species composition in the diet of the seals in these two areas also differed, with the seals in Bass Strait eating mainly N. gouldi, whereas the seals in southern waters fed on benthic octopods. The seals preyed on mainly adult cephalopods over the continental shelf. The size range and species composition of the diet varied according to the sample types, with faeces containing only small beaks relative to regurgitates and stomachs. Errors associated with sample types and application of regression equations are discussed.
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McIntosh, Rebecca R., Karina J. Sorrell, Sam Thalmann, Anthony Mitchell, Rachael Gray, Harley Schinagl, John P. Y. Arnould, Peter Dann, and Roger Kirkwood. "Sustained reduction in numbers of Australian fur seal pups: Implications for future population monitoring." PLOS ONE 17, no. 3 (March 18, 2022): e0265610. http://dx.doi.org/10.1371/journal.pone.0265610.
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Fur seal populations in the Southern Hemisphere were plundered in the late 1700s and early 1800s to provide fur for a clothing industry. Millions of seals were killed resulting in potentially major ecosystem changes across the Southern Hemisphere, the consequences of which are unknown today. Following more than a century of population suppression, partly through on-going harvesting, many of the fur seal populations started to recover in the late 1900s. Australian fur seals (Arctocephalus pusillus doriferus), one of the most geographically constrained fur seal species, followed this trend. From the 1940s to 1986, pup production remained at approximately 10,000 per year, then significant growth commenced. By 2007, live pup abundance had recovered to approximately 21,400 per year and recovery was expected to continue However, a species-wide survey in 2013 recorded a 20% decline, to approximately 16,500 live pups. It was not known if this decline was due to 2013 being a poor breeding year or a true population reduction. Here we report the results of a population-wide survey conducted in 2017 and annual monitoring at the most productive colony, Seal Rocks, Victoria that recorded a large decline in live pup abundance (-28%). Sustained lower pup numbers at Seal Rocks from annual counts between 2012–2017 (mean = 2908 ± 372 SD), as well as the population-wide estimate of 16,903 live pups in 2017, suggest that the pup numbers for the total population have remained at the lower level observed in 2013 and that the 5-yearly census results are not anomalies or representative of poor breeding seasons. Potential reasons for the decline, which did not occur range-wide but predominantly in the most populated and long-standing breeding sites, are discussed. To enhance adaptive management of this species, methods for future monitoring of the population are also presented. Australian fur seals occupy several distinct regions influenced by different currents and upwellings: range-wide pup abundance monitoring enables comparisons of ecosystem status across these regions. Forces driving change in Australian fur seal pup numbers are likely to play across other marine ecosystems, particularly in the Southern Hemisphere where most fur seals live.
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Tripovich, Joy S., Tracey L. Rogers, and Geoff Dutton. "Faecal testosterone concentrations and the acoustic behaviour of two captive male Australian fur seals." Australian Mammalogy 31, no. 2 (2009): 117. http://dx.doi.org/10.1071/am09009.
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Seasonal changes in reproductive and acoustic behaviour are potentially affected by hormonal fluctuations; however, as it is difficult to routinely sample marine mammals, these associations are mostly inferred. Australian fur seals are vocal marine mammals that have a highly synchronous breeding season. The present study collected information on the testosterone concentration in faeces, vocalisations and behaviour of two captive male Australian fur seals to determine whether there are any associations between these variables. Positive associations were evident between the non-interactive agonistic behaviours (Head sway, Lay down and Head up) and an increase in calling rate of the bark calls in males. Barks were highest during August through to October, corresponding to the breeding period, while faecal testosterone levels peaked in September, coinciding with the high frequency in the calling rates of barks. Guttural threat calls were rarely heard throughout the year, but peaked in August. This call was not frequently heard but was associated with specific behaviours that were produced during more intense fighting interactions. This study presents preliminary information on the vocalisations, behaviour and hormone profiles for two captive Australian fur seals. Future studies with increased sample sizes from both wild and captive animals would clarify the intricate association between these factors.
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Shaughnessy, Peter D., and Simon D. Goldsworthy. "Dispersion of long-nosed fur seals (Arctocephalus forsteri) determined by tagging." Australian Journal of Zoology 67, no. 3 (2019): 173. http://dx.doi.org/10.1071/zo20032.
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Long-nosed fur seals (Arctocephalus forsteri) were tagged as pups in colonies on Kangaroo Island, South Australia in eight consecutive pupping seasons from 1988–89 to 1995–96. Thirty-nine tagged animals were sighted on the southern Australian coast, being 0.89% of those tagged. They were aged from 9 months to 14 years 6 months, with half in their second and third years. Most records (88%) were of animals that moved eastwards. The most distant records were from Sydney in the east (1700 km), south of Tasmania in the south (1240 km) and Head of Bight in the west (700 km). One animal was seen twice, both times on the north coast of Kangaroo Island, once underwater and two years later ashore. Satellite telemetry studies of juvenile A. forsteri from Kangaroo Island showed that they typically forage in pelagic waters ~1000 km further south in association with the subtropical front. The study reported here shows that some animals tagged as pups disperse widely as juveniles around the southern Australian coast. The possibility of genetic interchange between breeding colonies is suggested by sightings of three tagged females aged 4 years and older at non-natal colonies.
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Arnould, J. P. Y., and R. M. Warneke. "Growth and condition in Australian fur seals (Arctocephalus pusillus doriferus) (Carnivora : Pinnipedia)." Australian Journal of Zoology 50, no. 1 (2002): 53. http://dx.doi.org/10.1071/zo01077.
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Mass and length growth models were determined for male (n = 69) and female (n = 163) Australian fur seals (Arctocephalus pusillus doriferus) collected at a breeding colony on Seal Rocks (38˚31′S, 145˚06′E), Bass Strait, in south-east Australia, between February and November during 1970–72. Growth was best described by the logistic model in males and the von Bertalanffy model in females. Asymptotic mass and length were 229 kg and 221 cm for males, and 85 kg and 163 cm for females. In all, 95% of asymptotic mass and length were attained by 11 years and 11 years, respectively, in males compared with 9 years and 5 years, respectively, in females. Males grew in length faster than females and experienced a growth spurt in mass coinciding with the onset of puberty (4–5 years). The onset of puberty in females occurs when approximately 86% of asymptotic length is attained. The rate of growth and sexual development in Australian fur seals is similar to (if not faster than) that in the conspecific Cape fur seal (A. p. pusillus), which inhabits the nutrient-rich Benguela current. This suggests that the low marine productivity of Bass Strait may not be cause of the slow rate of recovery of the Australian fur seal population following the severe over-exploitation of the commercial sealing era. Sternal blubber depth was positively correlated in adult animals with a body condition index derived from the residuals of the mass–length relationship (males: r2 = 0.38, n = 19, P < 0.001; females: r2 = 0.22, n = 92, P < 0.001), confirming the validity of using such indices on otariids. Sternal blubber depth varied significantly with season in adult animals. In males it was lowest in winter and increased during spring prior to the breeding season (r2 = 0.39, n = 19, P < 0.03) whereas in females it was greatest during winter (r2 = 0.05, n = 122, P< 0.05).
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Shaughnessy, Peter D., Mike Bossley, and A. O. Nicholls. "Fur seals and sea lions (family Otariidae) on the breakwaters at Adelaide." Australian Mammalogy 40, no. 2 (2018): 157. http://dx.doi.org/10.1071/am17001.
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Long-nosed fur seals (Arctocephalus forsteri) and Australian sea lions (Neophoca cinerea) on the breakwaters at the mouth of the Port River estuary at Adelaide’s Outer Harbor were counted from 2004 to 2015. Observed counts were modelled using a generalised linear model. Fur seal numbers have been increasing since 2011; for sea lions there was a small discernible annual trend in counts. Counts of fur seals varied seasonally; most annual maxima were in August or September with modelled peak numbers around 9–11 September. The maximum count of fur seals was 79 in September 2015. For sea lions, the model predicts annual peaks in the period 28 August to 19 September. The maximum count of sea lions was nine in September 2009. The haulout sites on the Outer Harbor breakwaters are easily accessible by boats, including pleasure craft. In particular, the seaward end of the outer breakwater is a popular spot with recreational anglers whose lines are often within a few metres of the seals. We propose that a management plan should be developed involving a study of the effect of boat approaches on seals utilising the Outer Harbor area followed by education coupled with enforcement.
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Littnan, CL, and JPY Arnould. "At-Sea Movements Of Female Australian Fur Seals Arctocephalus Pusillus Doriferus." Australian Mammalogy 24, no. 1 (2002): 65. http://dx.doi.org/10.1071/am02065.
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In May 1999, satellite transmitters were deployed on three lactating female Australian fur seals (Arctocephalus pusillus doriferus) at Kanowna Island (39� 10' S, 146� 18' E) and at-sea movements were recorded for 65 ? 174 days. The mean foraging trip and on-shore durations (8 and 2 days, respectively) were not significantly different to that previously reported for the species. The seals all foraged in three separate areas of Bass Strait with each individual repeatedly returning to the same general location. Movements during foraging trips fell into two distinct patterns. In one pattern, displayed by two individuals, the females travelled directly to a presumed foraging area. In this trip type, outward and return travel consisted of relatively constant headings at moderate speed (1.37 � 0.07 m/s) while the middle phase was characterised by repeated changes in direction within a small area and significantly lower speeds (0.82 � 0.07 m/s). The second pattern, displayed by the third individual, consisted of a looping path with relatively uniform average speed (1.14 � 0.06 m/s) throughout the trip. The three foraging areas were: 1) inshore area between Wilsons Promontory and Lakes Entrance; 2) offshore in proximity to The Skerries; and 3) up to 200 km south of Wilsons Promontory in central Bass Strait. The foraging areas used by these seals overlap with regions of commercial fishing effort raising the potential for some conflict.
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Knox, TC, AMM Baylis, and JPY Arnould. "Habitat use and diving behaviour of male Australian fur seals." Marine Ecology Progress Series 566 (February 27, 2017): 243–56. http://dx.doi.org/10.3354/meps12027.
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Hoskins, Andrew J., Daniel P. Costa, and John P. Y. Arnould. "Utilisation of Intensive Foraging Zones by Female Australian Fur Seals." PLOS ONE 10, no. 2 (February 18, 2015): e0117997. http://dx.doi.org/10.1371/journal.pone.0117997.
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Gibbens, John, Laura J. Parry, and John P. Y. Arnould. "Influences on fecundity in Australian fur seals (Arctocephalus pusillus doriferus)." Journal of Mammalogy 91, no. 2 (April 16, 2010): 510–18. http://dx.doi.org/10.1644/08-mamm-a-377.1.
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Arnould, John P. Y., and Roger Kirkwood. "Habitat selection by female Australian fur seals (Arctocephalus pusillus doriferus)." Aquatic Conservation: Marine and Freshwater Ecosystems 17, S1 (December 2007): S53—S67. http://dx.doi.org/10.1002/aqc.908.
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Littnan, CL, and AT Mitchell. "Australian And New Zealand Fur Seals At The Skerries, Victoria: Recovery Of A Breeding Colony." Australian Mammalogy 24, no. 1 (2002): 57. http://dx.doi.org/10.1071/am02057.
Full textAbstract:
The population size of Australian fur seals Arctocephalus pusillus doriferus and New Zealand fur seals A. forsteri at The Skerries, Victoria was estimated in two consecutive breeding seasons, 1999-2000 and 2000-2001 using both mark-recapture procedures and aerial surveys. 675 and 746 A. p. doriferus pups and 37 and 47 A. forsteri pups were captured and marked in 1999-2000 and 2000-2001, respectively. Resights (1999-2000 N = 3; 2000-2001 N = 6) were conducted 2 - 3 days after marking and pup population estimates were calculated using a modified Lincoln-Petersen estimate. The arithmetic mean for A. p. doriferus pup abundance was 1,867 in the first season and 2,237 in the second. A. forsteri abundance was 75 and 78, respectively. The A. p. doriferus population is estimated to have increased an average of 19.7% (r = 0.18) between 1999 and 2000. The arithmetic mean from five counts of aerial photographs of total animals present at the colony was 1,758 in 1999-2000 and 2,965 in 2000-2001. Due to high variation between counts, aerial surveys proved to be an inconsistent and inaccurate method for estimating the population of fur seals at The Skerries.
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Shaughnessy, PD, SV Briggs, and R. Constable. "Observations on Seals at Montague Island, New South Wales." Australian Mammalogy 23, no. 1 (2001): 1. http://dx.doi.org/10.1071/am01001.
Full textAbstract:
Australian fur-seals Arctocephalus pusillus doriferus and New Zealand fur-seals A. forsteri haul-out (come ashore) at the north end of Montague Island. They were counted from study boats on 82 occasions during nine trips to the island, each of about one week, between November 1997 and November 1998, and in July 1999 and April 2000. Highest numbers were recorded between August and October 1998, and more animals were ashore during 1997 and 1998 than Irvine et al. (1997) observed in 1993 and 1994. The maximum number of A. p. doriferus recorded ashore in this study was 540 in October 1998, compared with a little over 300 observed in September 1993. There are reports of a few fur-seal pups on Montague Island. An A. forsteri pup born there in the 1999/2000 summer survived for at least 4 months. Nevertheless, the island should be considered as supporting haul-out sites rather than breeding sites. A Subantarctic fur-seal A. tropicalis and an Australian sea-lion Neophoca cinerea were also recorded during the study. Seven juvenile A. p. doriferus were observed ashore with manmade debris (straps or portions of a trawl net) around their necks. Fur-seals at Montague Island generate interest because of tourism and interactions with local fisheries. Trends in their abundance should be monitored annually in March, for which there is a long-term data set, and in October, when they are most abundant.
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Back, Julia J., Andrew J. Hoskins, Roger Kirkwood, and John P. Y. Arnould. "Behavioral responses of Australian fur seals to boat approaches at a breeding colony." Nature Conservation 31 (December 18, 2018): 35–52. http://dx.doi.org/10.3897/natureconservation.31.26263.
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In Australia, a multi-million-dollar industry is based on viewing the Australian fur seal (Arctocephaluspusillusdoriferus), predominantly through boat visits to breeding colonies. Regulation of boat approaches varies by site and no systematic investigations have been performed to inform management guidelines. To investigate possible effects of disturbance, experimental boat approaches were made to a colony at Kanowna Island in northern Bass Strait and seal responses were monitored using instantaneous scan sampling. Colony attendance (individuals remaining ashore) was found to be influenced by approach distance and time of day, but was not affected by environmental variables or season, whereas onshore resting behavior was influenced by approach distance, time of day, ambient temperature and wind direction. Onshore resting behavior decreased following experimental boat approaches to 75 m, but changes in abundance of individuals ashore were not observed at this distance. In contrast, approaches to 25 m elicited a strong response, with a steep decline in the number of individuals ashore. This response was strongest when approaches occurred in the morning, with a decline of approximately 47% of individuals, compared to a decline of 21% during afternoon approaches. With regard to onshore resting behavior, afternoon approaches to 75 m led to minimal response. The remaining three combinations of approach distance and time of day had a similar pattern of reductions in the proportion of individuals engaging in onshore resting behavior. The strongest response was again seen during approaches to 25 m conducted in the morning. These behavior changes suggest that unrestricted boat-based ecotourism at Australian fur seal colonies has the potential to increase energy expenditure and reduce the number of seals ashore. Increasing minimum approach distances to ≥75 m and/or restricting visits to afternoons may minimize these impacts at Kanowna Island during the post-molt and non-breeding seasons. As several studies have demonstrated considerable intra-species variation in seal responses to boat approaches, research at other colonies is needed before these findings can be generalized to the remainder of the Australian fur seal population.
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Townrow, K., and P. D. Shaughnessy. "Fur seal skull from sealers' quarters at Sandy Bay, Macquarie Island, Southern Ocean." Polar Record 27, no. 162 (July 1991): 245–48. http://dx.doi.org/10.1017/s0032247400012651.
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AbstractFur seals were exterminated from Macquarie Island about 20 years after discovery of the island in 1810. Their specific identity is unknown. Few fur seals were reported at the island until it was occupied by the Australian National Antarctic Research Expeditions in 1948. Fur seal numbers are now increasing. An archaeological excavation at a sealers' quarters at Sandy Bay in 1988 revealed the fragmented skull of a young Antarctic fur sealArctocephalus gazella1.1 m below the surface in a layer dated in the 1870s and 1880s. This period coincides with the recovery of fur seal populations in the South Atlantic Ocean following earlier harvesting. Elsewhere it has been argued that the Antarctic fur seal is unlikely to have been the original fur seal at Macquarie Island because few individuals of that species are ashore in winter, which is the season when the island was discovered and fur-seal harvesting began. It is concluded that the Sandy Bay skull is from a vagrant animal.
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Kirkwood, R., N. Gales, M. Lynch, and P. Dann. "Satellite Tracker Deployments On Adult, Male Australian Fur Seals (Arctophalus Pusillus Doriferus): Methods And Preliminary Results." Australian Mammalogy 24, no. 1 (2002): 73. http://dx.doi.org/10.1071/am02073.
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In May 1999, four adult male, Australian fur seals (Arctocephalus pusillus doriferus) from the Seal Rocks colony, Victoria, were fitted with satellite transmitters that provided locations for between 2 and 7 months. Foraging trips during winter and early spring averaged 7.4 days (range for all trips 0.9 to 24.6) and between-trip rests lasted 2.8 days (range 0.3 to 5.7). Between-trip rest sites included Seal Rocks, other colonies and other haul-out sites. The seals foraged mostly in western Bass Strait and in water depths < 100 m.
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Page, B., J. McKenzie, and SD Goldsworthy. "Dietary resource partitioning among sympatric New Zealand and Australian fur seals." Marine Ecology Progress Series 293 (2005): 283–302. http://dx.doi.org/10.3354/meps293283.
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Pemberton, D., R. Kirkwood, R. Gales, and D. Renouf. "SIZE AND SHAPE OF MALE AUSTRALIAN FUR SEALS, ARCTOCEPHALUS PUSILLUS DORIFERUS." Marine Mammal Science 9, no. 1 (January 1993): 99–103. http://dx.doi.org/10.1111/j.1748-7692.1993.tb00433.x.
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Tripovich, Joy S., Sophie Hall-Aspland, Isabelle Charrier, and John P. Y. Arnould. "The Behavioural Response of Australian Fur Seals to Motor Boat Noise." PLoS ONE 7, no. 5 (May 18, 2012): e37228. http://dx.doi.org/10.1371/journal.pone.0037228.
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Hume, F., JPY Arnould, R. Kirkwood, and P. Davis. "Extended Maternal Dependence By Juvenile Australian Fur Seals (Arctocephalus Pusillus Doriferus)." Australian Mammalogy 23, no. 1 (2001): 67. http://dx.doi.org/10.1071/am01067.
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AUSTRALIAN fur seal (Arctocephalus pusillus doriferus) cows mature at 3 - 6 years of age and, thereafter, are able to give birth to a single pup each year (Warneke and Shaughnessy 1985; Warneke 1995). Pups are born from late October to December and are usually nursed for 8 - 11 months (Warneke and Shaughnessy 1985), however, extended dependency into a second or third year has been recorded (Stirling and Warneke 1971). At Seal Rocks, Victoria, one of nine breeding sites for A. p. doriferus (Warneke 1988; Pemberton and Kirkwood 1994), 11% of young that were observed in association with cows were older than one year (Shaughnessy and Warneke 1987).
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Lawson, T. J., Chris Wilcox, Karen Johns, P. Dann, and Britta Denise Hardesty. "Characteristics of marine debris that entangle Australian fur seals (Arctocephalus pusillus doriferus) in southern Australia." Marine Pollution Bulletin 98, no. 1-2 (September 2015): 354–57. http://dx.doi.org/10.1016/j.marpolbul.2015.05.053.
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Lynch, Michael, Trevor K. Taylor, Pádraig J. Duignan, Jane Swingler, Marc Marenda, John P. Y. Arnould, and Roger Kirkwood. "Mycoplasmas in Australian fur seals (Arctocephalus pusillus doriferus): identification and association with abortion." Journal of Veterinary Diagnostic Investigation 23, no. 6 (November 2011): 1123–30. http://dx.doi.org/10.1177/1040638711425699.
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Bacteria from the genus Mycoplasma are common inhabitants of the respiratory, gastrointestinal, and genital tracts of mammals. The understanding of the pathological significance of mycoplasmas in seals is poor, as few studies have utilized the specific culture techniques required to isolate these bacteria. The current study surveyed for the Mycoplasma species present in Australian fur seals ( Arctocephalus pusillus doriferus) and investigated the association between infection and pathology. Mycoplasmas were found in the nasal cavities of 55/80 (69%) of apparently healthy individuals. Isolates from 18 individuals were investigated through 16S ribosomal RNA sequencing, and 3 species were identified: M. zalophi, M. phocae, and Mycoplasma sp. (GenBank no. EU714238.1), all of which had previously been isolated from Northern Hemisphere pinnipeds. In addition, mycoplasmas were isolated from the lungs of 4 out of 16 juveniles and 1 out of 5 adults sampled at necropsy. Isolates obtained were M. zalophi, Mycoplasma sp. EU714238.1, and M. phocicerebrale, but infection was not associated with lung pathology in these age classes. Inflammatory disease processes of the heart and/or lungs were present in 12 out of 32 (38%) aborted fetuses on microscopic examination. Predominant findings were interstitial pneumonia, pericarditis, and myocarditis. Mycoplasma phocicerebrale was isolated from the thymus of an aborted fetus, and 3 out of 11 (27%) fetuses with inflammatory heart or lung lesions were PCR-positive for Mycoplasma. In conclusion, several species of Mycoplasma are part of the normal flora of the nasal cavity of Australian fur seals, and some mycoplasmas may be associated with abortion in this species of seal.
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Brunner, S., P. D. Shaughnessy, and M. M. Bryden. "Geographic variation in skull characters of fur seals and sea lions (family Otariidae)." Australian Journal of Zoology 50, no. 4 (2002): 415. http://dx.doi.org/10.1071/zo01056.
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Geographic variation was observed in skulls of several otariid species, with a general change in size corresponding with a change in latitude and primary productivity. The largest specimens were from cool temperate localities, conforming mostly to Rensch's rule. Skulls of Australian sea lions from Western Australia were generally smaller in condylobasal length, but were more robust than those from South Australia. The subantarctic fur seal did not conform to Bergmann's rule: skulls from Amsterdam Island (37�55´S) were largest, those from Gough Island (40�20´S) intermediate and those from Marion Island (46�55´S) the smallest. For both sexes, skulls of southern sea lions from the Falkland Islands were smaller than their equivalents from mainland South America. Similarly, skulls of South African fur seals from south-east South Africa appeared smaller than those from the west coast of South Africa and Namibia; skulls from Namibia grouped separately from those of south-east and west coast, South Africa. We postulate that the Otariidae are in the process of species divergence, much of which may be driven by local factors, particularly latitude and resources.
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Arnould, John PY, and Mark A. Hindell. "Dive behaviour, foraging locations, and maternal-attendance patterns of Australian fur seals (Arctocephalus pusillus doriferus)." Canadian Journal of Zoology 79, no. 1 (January 1, 2001): 35–48. http://dx.doi.org/10.1139/z00-178.
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The dive behaviour, foraging locations, and colony-attendance patterns of female Australian fur seals (Arctocephalus pusillus doriferus) from Kanowna Island (39°10'S, 146°18'E) in Bass Strait, southeastern Australia, were determined throughout lactation during 19971999. Foraging-trip durations increased as lactation progressed, being shortest in summer (3.71 ± 0.24 days; mean ± 1 SE) and longest in winter (6.77 ± 0.57 days, P < 0.05), but maternal-attendance periods did not differ in duration (1.70 ± 0.10 days, P > 0.5). Individual mean attendance periods and trip durations were positively correlated (r2 = 0.21, P < 0.005). Diving commenced shortly after seals left the colony (2.6 ± 0.4 h), was continuous for long periods (up to 36 h), occurred mostly during daylight hours, and lacked regular diel variation in depth. The majority of dives (78%) were typically U-shaped and reached depths corresponding to the prevailing depths in Bass Strait (6585 m), indicating that these animals forage mostly on the benthos of the shallow continental shelf in this region. Such behaviour is unusual for fur seals but is reminiscent of that of some sea lion species. Mean dive durations varied between 2.0 and 3.7 min (maximum 8.9 min) and the theoretical aerobic dive limit (3.914.26 min) was exceeded on 17.3% of dives. Dive frequency (8.3 ± 0.6/h) and the proportion of time at sea spent diving (40.7 ± 2.1%) were weakly negatively related to the duration of the foraging trip (r2 = 0.07, P < 0.004, and r2 = 0.13, P < 0.0001, respectively). Data from at-sea locations showed that lactating females forage almost exclusively within Bass Strait during all seasons.
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Brunner, S. "Cranial morphometrics of the southern fur seals Arctocephalus forsteri and A. pusillus (Carnivora : Otariidae)." Australian Journal of Zoology 46, no. 1 (1998): 67. http://dx.doi.org/10.1071/zo97020.
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The identification and classification of unknown specimens of Arctocephalus from regions of Australasia has proven difficult. Skulls from the New Zealand fur seal (Arctocephalus forsteri) and the Australian fur seal (A. pusillus doriferus), and data from specimens of the South African fur seal (A. p. pusillus), were examined. A visual method was devised to identify and separate A. p. doriferus from A. forsteri for both sexes and for most physiological age-groups. A statistical method for morphometric separation of these species was applied to adult specimens. Characteristics of males and females for both species fell into two broad categories: sexually dimorphic – mainly those characters that increase the ability of males to hold and defend territories; and non-dimorphic – those of functional importance. Studies of geographical variation showed that adult male A. forsteri from Australia were generally larger than those from Macquarie Island and New Zealand. Characteristics of A. p. doriferus were generally larger than those of A. p. pusillus. Nine specimens of New Zealand fur seals were morphologically different from the typical A. forsteri, which indicates the presence of extreme outliers or hybrids in the sample.
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Meyers, Nelle, Cassie N. Speakman, Nicole A. S. Y. Dorville, Mark A. Hindell, Jayson M. Semmens, Jacquomo Monk, Alistair M. M. Baylis, et al. "The cost of a meal: factors influencing prey profitability in Australian fur seals." PeerJ 9 (December 8, 2021): e12608. http://dx.doi.org/10.7717/peerj.12608.
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Knowledge of the factors shaping the foraging behaviour of species is central to understanding their ecosystem role and predicting their response to environmental variability. To maximise survival and reproduction, foraging strategies must balance the costs and benefits related to energy needed to pursue, manipulate, and consume prey with the nutritional reward obtained. While such information is vital for understanding how changes in prey assemblages may affect predators, determining these components is inherently difficult in cryptic predators. The present study used animal-borne video data loggers to investigate the costs and benefits related to different prey types for female Australian fur seals (Arctocephalus pusillus doriferus), a primarily benthic foraging species in the low productivity Bass Strait, south-eastern Australia. A total of 1,263 prey captures, resulting from 2,027 prey detections, were observed in 84.5 h of video recordings from 23 individuals. Substantial differences in prey pursuit and handling times, gross energy gain and total energy expenditure were observed between prey types. Importantly, the profitability of prey was not significantly different between prey types, with the exception of elasmobranchs. This study highlights the benefit of animal-borne video data loggers for understanding the factors that influence foraging decisions in predators. Further studies incorporating search times for different prey types would further elucidate how profitability differs with prey type.
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Pemberton, D., NP Brothers, and R. Kirkwood. "Entanglement of Australian fur seals in man-made debris in Tasmanian waters." Wildlife Research 19, no. 2 (1992): 151. http://dx.doi.org/10.1071/wr9920151.
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Observations were made of neck collars of man-made debris on Australian fur seals in Tasmanian waters. These included 47 sightings on six breeding colonies in Bass Strait and 22 on five haul-out sites, one in Bass Strait and four in southern Tasmania. The incidence of entanglement of the population calculated for the southern waters was 1.9 +/- 0.7% (n = 10). Of items identified, polyethylene trawl-net accounted for 40% of neck collars, polypropylene packaging straps 30%, monofilament nets (gill nets) 15% and nylon rope 15%. A variety of colours of polypropylene straps were observed, which indicate a variety of sources of the material. The majority, 66%, of entangled animals were juveniles or subadults; a further 16% were non-breeding adult males and 18% were breeding adults. The neck collars were causing obvious physical injury to 73% of the animals observed and in the two worst cases the collars had cut through the oesophagus. Collars made of traw1.net are the greatest cause for concern as they are large, buoyant and originate from a fishery that is increasing in size and produces a lot of debris. The high incidence of neck collars on Australian fur seals indicates that entanglement is a potential threat to the seal population. This effect may not be reflected in the number of pups born until the animals currently being entangled reach breeding age.
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CHABOT, DENIS. "Scientific Correspondence Relationship Between Mass and Body Length in Australian fur Seals." Marine Mammal Science 10, no. 2 (April 1994): 250–51. http://dx.doi.org/10.1111/j.1748-7692.1994.tb00270.x.
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Garlepp, Linda, Murray Logan, and Roger Kirkwood. "Behavioral responses of Australian fur seals (Arctocephalus pusillus doriferus) to environmental variations." Marine Mammal Science 30, no. 3 (December 17, 2013): 978–93. http://dx.doi.org/10.1111/mms.12094.
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