Fur Seals and Sea Lions

2013 ◽  
Author(s):  
Roger Kirkwood ◽  
Simon Goldsworthy
Keyword(s):  
Evolutionary Ecology ◽  
Conservation Status ◽  
Sea Lions ◽  
Australian Sea Lion ◽  
Fur Seals ◽  
Fur Seal ◽  
History Of ◽  
Near Shore ◽  
New Zealand Fur Seal ◽  
Near Extinction

Fur seals and sea lions are charismatic, large carnivores that engage us with both their skill and playful antics. Although all species in Australian waters were harvested to near extinction 200 years ago, fur seals are recovering and are now common in near-shore waters across southern Australia. Sea lions, however, are endangered. Their populations appear not to have recovered like fur seals and are declining at some locations. Fur seals and sea lions are important top level predators and play an important role in Australia’s temperate marine ecosystems. Key threats they currently face relate to human activities, particularly interactions with fisheries. This book outlines the comparative evolutionary ecology, biology, life-history, behaviour, conservation status, threats, history of human interactions and latest research on the three species of otariids that live in the waters of southern Australia: the Australian fur seal, New Zealand fur seal and Australian sea lion. It also includes brief descriptions of Antarctic and Subantarctic seals that occupy the Antarctic pack-ice and remote Australian territories of Macquarie Island and Heard Island.

Seal survey in the Great Australian Bight region of Western Australia

1999 ◽  
Vol 26 (3) ◽  
pp. 383 ◽  
Author(s):  
T. E. Dennis ◽  
P. D. Shaughnessy
Keyword(s):  
New Zealand ◽  
Western Australia ◽  
South Australia ◽  
Sea Lion ◽  
Sea Lions ◽  
Australian Sea Lion ◽  
Fur Seals ◽  
Fur Seal ◽  
New Zealand Fur Seal ◽  
Great Australian Bight

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.

Rate of passage of digesta through the alimentary tract of the New Zealand fur seal (Arctocephalus forsteri) and the Australian sea lion (Neophoca cinerea) (Carnivora : Otariidae)

1999 ◽  
Vol 47 (2) ◽  
pp. 193 ◽  
Author(s):  
B. Bodley ◽  
the late J. R. Mercer ◽  
M. M. Bryden
Keyword(s):  
New Zealand ◽  
Feeding Time ◽  
Sea Lions ◽  
First Feeding ◽  
Neophoca Cinerea ◽  
Australian Sea Lion ◽  
Fur Seals ◽  
The Mean ◽  
Initial Recovery ◽  
New Zealand Fur Seal

The inert marker titanium dioxide was added to the food of two male New Zealand fur seals (Arctocephalus forsteri) and three Australian sea lions (Neophoca cinerea) in Taronga Zoo, Sydney, in a series of 15 trials. The enclosures were checked constantly during daylight hours, and defaecation times and location of samples noted. Samples were collected at feeding times, at approximately 0930, 1300 and 1500 hours. During the night the animals were checked at 30-min intervals, the location of samples noted, and samples collected at the first feeding time next morning. Faecal collections were made for up to 50 h after dosing. Marker concentrations in faecal dry matter were determined and mean retention times calculated from the mean concentration-time curves. The mean time between dosing and first recovery of marker (Initial Recovery Time) was 4 h for A. forsteri and 6.5 h for N. cinerea. Mean retention time, a better index of rate of passage of digesta, was 14.6 h for A. forsteri and 14.9 h for N. cinerea. Thus, the marker concentration curves indicated a rapid rate of food transit through the gastrointestinal tract, as has been observed in several (but not all) pinniped species.

Australian fur seals establish haulout sites and a breeding colony in South Australia

2010 ◽  
Vol 58 (2) ◽  
pp. 94 ◽  
Author(s):  
Peter D. Shaughnessy ◽  
Jane McKenzie ◽  
Melanie L. Lancaster ◽  
Simon D. Goldsworthy ◽  
Terry E. Dennis
Keyword(s):  
Mitochondrial Dna ◽  
New Zealand ◽  
South Australia ◽  
Breeding Colony ◽  
Mitochondrial Dna Control Region ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Fur Seals ◽  
Fur Seal ◽  
New Zealand Fur Seal

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.

Status of Australian sea lions, Neophoca cinerea, and New Zealand fur seals, Arctocephalus forsteri, on Eyre Peninsula and the far west coast of South Australia

2005 ◽  
Vol 32 (1) ◽  
pp. 85 ◽  
Author(s):  
P. D. Shaughnessy ◽  
T. E. Dennis ◽  
P. G. Seager
Keyword(s):  
New Zealand ◽  
West Coast ◽  
South Australia ◽  
Sea Lion ◽  
The West ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Fur Seals ◽  
Fur Seal ◽  
New Zealand Fur Seal

Two seal species breed on the west coast of South Australia, the Australian sea lion, Neophoca cinerea, and the New Zealand fur seal, Arctocephalus forsteri. Aerial surveys were conducted at intervals of ~3 months between April 1995 and June 1997 to determine the breeding status of sea lions and timing of pupping seasons. Ground surveys between October 1994 and April 2004 aimed at counting sea lions and fur seals, particularly pups. In all, 27 sites were examined. Six new sea lion breeding colonies were documented, at Four Hummocks, Price, North Rocky, Dorothee, West Waldegrave and Nicolas Baudin Islands. All were found or confirmed by ground survey. Pup numbers were equivalent to 12% of the total number of pups estimated in surveys conducted from 1987 to 1992, but primarily in 1990. The sighting of brown pups on aerial surveys of Ward Island, Middle and Western Nuyts Reef supports earlier indications, based on dead pups, that they are breeding colonies. The timing of pupping seasons is not synchronous; estimates are presented for colonies between 1995 and early in 2004, with predictions to the end of 2005. The abundance estimates of sea lion pups highlight the importance of visiting a colony early in the pupping season to determine when pupping begins and ~5 months later when the maximum number of pups is expected. For the New Zealand fur seal, small numbers of pups were recorded at Dorothee, West Waldegrave and Nicolas Baudin Islands, and at Nuyts Reef. These and the previously unknown sea lion breeding colonies on the west coast of South Australia suggest that further colonies may remain to be documented. Because planning for aquaculture ventures is active in South Australia, it is important that the localities and status of sea lion and fur seal colonies be established unequivocally to ensure that the need for Prohibited Area status for islands with breeding colonies and for Marine Protected Areas around them is noted.

Records of vagrant fur seals (family Otariidae) in South Australia

2014 ◽  
Vol 36 (2) ◽  
pp. 154 ◽  
Author(s):  
Peter D. Shaughnessy ◽  
Catherine M. Kemper ◽  
David Stemmer ◽  
Jane McKenzie
Keyword(s):  
New Zealand ◽  
South Australia ◽  
The South ◽  
South Indian Ocean ◽  
Fur Seals ◽  
South Indian ◽  
Fur Seal ◽  
New Zealand Fur Seal ◽  
The Antarctic ◽  
Subantarctic Fur Seals

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.

scholarly journals Fur seals do, but sea lions don't — cross taxa insights into exhalation during ascent from dives

2021 ◽  
Vol 376 (1830) ◽  
pp. 20200219 ◽  
Author(s):  
Sascha K. Hooker ◽  
Russel D. Andrews ◽  
John P. Y. Arnould ◽  
Marthán N. Bester ◽  
Randall W. Davis ◽  
...  
Keyword(s):  
Shallow Water ◽  
Decompression Sickness ◽  
Mammal Species ◽  
Free Living ◽  
Video Cameras ◽  
Sea Lions ◽  
Fur Seals ◽  
Fur Seal ◽  
The Antarctic ◽  
Management Issues

Management of gases during diving is not well understood across marine mammal species. Prior to diving, phocid (true) seals generally exhale, a behaviour thought to assist with the prevention of decompression sickness. Otariid seals (fur seals and sea lions) have a greater reliance on their lung oxygen stores, and inhale prior to diving. One otariid, the Antarctic fur seal ( Arctocephalus gazella ), then exhales during the final 50–85% of the return to the surface, which may prevent another gas management issue: shallow-water blackout. Here, we compare data collected from animal-attached tags (video cameras, hydrophones and conductivity sensors) deployed on a suite of otariid seal species to examine the ubiquity of ascent exhalations for this group. We find evidence for ascent exhalations across four fur seal species, but that such exhalations are absent for three sea lion species. Fur seals and sea lions are no longer genetically separated into distinct subfamilies, but are morphologically distinguished by the thick underfur layer of fur seals. Together with their smaller size and energetic dives, we suggest their air-filled fur might underlie the need to perform these exhalations, although whether to reduce buoyancy and ascent speed, for the avoidance of shallow-water blackout or to prevent other cardiovascular management issues in their diving remains unclear. This article is part of the theme issue ‘Measuring physiology in free-living animals (Part I)’.

Fur seals and sea lions (family Otariidae) on the breakwaters at Adelaide

2018 ◽  
Vol 40 (2) ◽  
pp. 157
Author(s):  
Peter D. Shaughnessy ◽  
Mike Bossley ◽  
A. O. Nicholls
Keyword(s):  
Linear Model ◽  
River Estuary ◽  
Management Plan ◽  
Annual Trend ◽  
Sea Lions ◽  
Neophoca Cinerea ◽  
Fur Seals ◽  
Fur Seal ◽  
Harbor Area

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.

Changes in the abundance of New Zealand fur seals, Arctocephalus forsteri, on Kangaroo Island, South Australia

1995 ◽  
Vol 22 (2) ◽  
pp. 201 ◽  
Author(s):  
PD Shaughnessy ◽  
SD Goldsworthy ◽  
JA Libke
Keyword(s):  
New Zealand ◽  
South Australia ◽  
Early Years ◽  
Mark Recapture ◽  
Fur Seals ◽  
Fur Seal ◽  
Rate Of Increase ◽  
New Zealand Fur Seal ◽  
Breeding Seasons ◽  
Made In

Kangaroo Island was an important seal-harvesting site during the early years of European colonisation of Australia. A recent survey of the New Zealand fur seal, Arctocephalus forsteri, in South and Western Australia indicates that Kangaroo I. is still an important centre for the species. In order to determine changes in the abundance of the population, numbers of pups were determined at four colonies on Kangaroo Island by mark-recapture in up to five breeding seasons from 1988-89 to 1992-93. Clipping was the preferred technique for mark-recapture estimation of pups because it was quick, easy and effective. Recaptures were conducted visually; they were repeated several times in each season to improve precision of the estimates. No pups were marked between recaptures in order to minimise disturbance. Assumptions made in estimating population size by the mark-recapture technique pertinent to this study are reviewed. Pup numbers increased at three colonies: at Cape Gantheaume, from 458 to 867 over five years (with exponential rate of increase r = 0.16, n = 5); at Nautilus North, from 182 to 376 over five years (at r = 0.19, n = 4); and at North Casuarina Islet, from 442 to 503 over four years (at r = 0.043, n = 2). Rates of increase in the first two colonies are similar to those at the most rapidly increasing fur seal populations in the Southern Hemisphere. The Kangaroo I. population is estimated to be 10000 animals in 1992-93. It is likely to be at the recolonisation phase of growth, with high rates of increase at individual colonies (or parts of colonies) resulting from local immigration. As space does not appear to be limiting expansion in these colonies, fur seal numbers may continue to increase there.

Trends in abundance of New Zealand fur seals, Arctocephalus forsteri, at the Neptune Islands, South Australia

2002 ◽  
Vol 29 (4) ◽  
pp. 363 ◽  
Author(s):  
P. D. Shaughnessy ◽  
A. McKeown
Keyword(s):  
New Zealand ◽  
South Australia ◽  
The South ◽  
The North ◽  
Fur Seals ◽  
Fur Seal ◽  
Seal Population ◽  
Island Group ◽  
Direct Counting ◽  
New Zealand Fur Seal

At the Neptune Islands in early February 2000 at the end of the 1999–2000 pupping season, the abundance of New Zealand fur seal pups was determined using a mark–recapture technique in large colonies and by direct counting in small ones. Pups (n = 2355) were marked by clipping hair on the head to reveal light-coloured underfur. At the North Neptune group, there were 4221 pups and at the South Neptune group 1767 pups, making a total of 5988 pups for the Neptune Island group as a whole. At the North Neptune Islands, pup numbers increased by 53% since February 1993, from 2756 to 4221. For the South Neptune group, pup numbers decreased by 6.7%, from 1893 to 1767. The decrease was spread over most colonies on the island. The large increase in pup numbers at the North Neptune group indicates that the population there is in the recolonisation phase of growth; at the South Neptune group, the fur seal population is likely to be in the maturity phase, with fluctuations in size expected in the future. The Neptune Island group supports the largest aggregation of pinnipeds in Australia.

scholarly journals The oldest known fur seal

2015 ◽  
Vol 11 (2) ◽  
pp. 20140835 ◽  
Author(s):  
Robert W. Boessenecker ◽  
Morgan Churchill
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Southern California ◽  
Middle Miocene ◽  
Sea Lions ◽  
Fur Seals ◽  
Fur Seal ◽  
Fossil Records ◽  
Phylogenetic Affinities

The poorly known fossil record of fur seals and sea lions (Otariidae) does not reflect their current diversity and widespread abundance. This limited fossil record contrasts with the more complete fossil records of other pinnipeds such as walruses (Odobenidae). The oldest known otariids appear 5–6 Ma after the earliest odobenids, and the remarkably derived craniodental morphology of otariids offers few clues to their early evolutionary history and phylogenetic affinities among pinnipeds. We report a new otariid, Eotaria crypta , from the lower middle Miocene ‘Topanga’ Formation (15–17.1 Ma) of southern California, represented by a partial mandible with well-preserved dentition. Eotaria crypta is geochronologically intermediate between ‘enaliarctine’ stem pinnipedimorphs (16.6–27 Ma) and previously described otariid fossils (7.3–12.5 Ma), as well as morphologically intermediate by retaining an M 2 and a reduced M 1 metaconid cusp and lacking P 2–4 metaconid cusps. Eotaria crypta eliminates the otariid ghost lineage and confirms that otariids evolved from an ‘enaliarctine’-like ancestor.

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