Australian fur seals, Arctocephalus pusillus doriferus: pup numbers at Lady Julia Percy Island, Victoria, and a synthesis of the species' population status

2002 ◽  
Vol 29 (2) ◽  
pp. 185 ◽  
Author(s):  
P. D. Shaughnessy ◽  
R. J. Kirkwood ◽  
R. M. Warneke
Keyword(s):  
New Zealand ◽  
Adult Male ◽  
Arithmetic Mean ◽  
Population Status ◽  
Guard Hair ◽  
New Born ◽  
Sea Lions ◽  
Fur Seals ◽  
Fur Seal ◽  
Species Population

The abundance of Australian fur seal pups was determined at Lady Julia Percy Island in early January 2000 when the average age of pups was 5 weeks. A mark-recapture procedure with repeated recapture sessions was used to estimate abundance of pups in six accessible breeding areas. Pups (n = 1836) were marked by clipping guard hair on the head. Recaptures were conducted visually on 2-4 occasions, when a mean of 41% of sighted pups had been marked. Pup numbers were calculated using a modified Petersen estimate and combined by taking their arithmetic mean. The combined estimate in the accessible breeding areas was 4487 380 pups were counted at two inaccessible sites and 347 dead pups were recorded. Overall, the estimate of abundance for Lady Julia Percy Island was 5214 pups. This exceeds three previous estimates of doubtful veracity for pupping seasons in 1935-36, 1975-76 and 1986-87, and is the greatest number of pups recorded at any Australian fur seal colony. Summation of the most recent estimates of abundance of Australian fur seal pups in all colonies indicates pup production of 16 900 per annum in the 1990s. New Zealand fur seals were also breeding on the island (a mating and four new-born pups were recorded) and two adult male Australian sea lions were observed.

Australian fur seals at Seal Rocks, Victoria: pup abundance by mark - recapture estimation shows continued increase

2000 ◽  
Vol 27 (6) ◽  
pp. 629 ◽  
Author(s):  
P. D. Shaughnessy ◽  
S. K. Troy ◽  
R. Kirkwood ◽  
A. O. Nicholls
Keyword(s):  
Confidence Intervals ◽  
Arithmetic Mean ◽  
Rapid Rate ◽  
Exponential Rate ◽  
Guard Hair ◽  
Mark Recapture ◽  
Fur Seals ◽  
Fur Seal ◽  
Rate Of Increase ◽  
Breeding Seasons

The abundance of Australian fur seal pups was determined at Seal Rocks, Westernport, Victoria in late December 1997 using a mark–recapture procedure with repeated recapture sessions. Pups (n = 1291) were marked by clipping the black guard hair on the head to reveal lighter underfur. Recaptures from the whole colony were made on eight occasions 1–3 days later. In the recapture sessions, a mean of 32% of sighted pups had been marked. Estimates of pup numbers over the eight recapture sessions were calculated using the Petersen estimate and then combined by taking their arithmetic mean. The combined estimate was 4024 (95% confidence range 3908–4141). In 1991–92, a similar procedure led to an estimate of pup numbers of 2817 (95% confidence range 2703–2930). For both breeding seasons, estimates of pup numbers from each recapture session were also combined assuming a joint hypergeometric distribution; there was little difference in the results from the two procedures, although the confidence intervals for the hypergeometric mean were smaller than those for the arithmetic mean. From 1991–92 to 1997–98, pup numbers increased by 43%, at an exponential rate of 0.059 (95% confidence range 0.0526–0.0664), equivalent to 6.1% per annum (5.4–6.9%). This is greater than the rate of increase of pups at the colony between 1968–69 and 1991–92, which was 0.023 (95% confidence range 0.0198–0.0268), equivalent to 2.4% per annum (2.0–2.7%). Because of the rapid rate of increase of the Australian fur seal colony at Seal Rocks and the importance of the locality for tourism, we recommend that the abundance of pups there be determined every 3–5 years using a mark–recapture technique.

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.

Morphology, age and survival of adult male New Zealand fur seals, Arctocephalus forsteri, in South Australia

1999 ◽  
Vol 26 (1) ◽  
pp. 21 ◽  
Author(s):  
S. K. Troy ◽  
R. Mattlin ◽  
P. D. Shaughnessy ◽  
P. S. Davie
Keyword(s):  
New Zealand ◽  
Adult Male ◽  
South Australia ◽  
Canine Tooth ◽  
Linear Measurements ◽  
Predictive Equations ◽  
Fur Seals ◽  
Fur Seal ◽  
The Mean ◽  
Breeding Seasons

Nineteen adult male New Zealand fur seals, Arctocephalus forsteri, were marked and measured at the start of the breeding seasons in November 1992 and 1993 at Cape Gantheaume, Kangaroo Island in South Australia. The age of each seal was estimated from the number of cementum layers in a post-canine tooth. The males that were attempting to hold territories were 7–15 years old and the heaviest was 160 kg. The mass of males could be predicted accurately from linear measurements and several predictive equations enable estimation of mass in the field. The mean annual survival rate for adult male New Zealand fur seals was 76%, which is higher than that in other fur seal species, perhaps reflecting the expanding nature of the A. forsteri population in Australia.

Impact Of Colonial Sealing On Seal Stocks Around Australia, New Zealand And Subantarctic Islands Between 150 And 170 Degrees East

2002 ◽  
Vol 24 (1) ◽  
pp. 117 ◽  
Author(s):  
JK Ling
Keyword(s):  
New Zealand ◽  
Elephant Seal ◽  
Southern Elephant Seal ◽  
Mirounga Leonina ◽  
Sources Of Information ◽  
Sea Lions ◽  
Fur Seals ◽  
Fur Seal ◽  
Seal Oil ◽  
The Impact

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.

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.

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.

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.

Seasonal dive behaviour of lactating New Zealand fur seals (Arctocephalus forsteri)

1998 ◽  
Vol 76 (2) ◽  
pp. 350-360 ◽  
Author(s):  
R H Mattlin ◽  
N J Gales ◽  
D P Costa
Keyword(s):  
New Zealand ◽  
Dive Depth ◽  
Dive Duration ◽  
Early Summer ◽  
Late Winter ◽  
Individual Values ◽  
Dive Behaviour ◽  
Fur Seals ◽  
Fur Seal ◽  
Bay Islands

The dive behaviour of 18 female New Zealand fur seals (Arctocephalus forsteri) from Taumaka, Open Bay Islands, New Zealand (43°52'S, 168°53'E), was recorded during early (summer; December-February), mid (autumn; March-May), and late (winter; June-August) lactation. Mean dive depth, dive duration, and bottom time for dives >=6 m in depth increased from summer through winter. Variation in individual seal dive behaviour within a season accounted for approximately 11, 9, and 11% of the observed difference between seasons in dive depth, dive duration, and bottom time, respectively. Seasonal dive data (mean ± 1 SD) were as follows: summer: dive depth 30 ± 37 m, dive duration 1.4 ± 1.1 min, and bottom time 0.5 ± 0.6 min; autumn: dive depth 54 ± 47 m, dive duration 2.4 ± 1.3 min, and bottom time 1.0 ± 0.8 min; winter: dive depth 74 ± 64 m, dive duration 2.9 ± 1.5 min, and bottom time 1.2 ± 1.1 min. Maximum recorded dive depth was 274 m for a 5.67-min dive in autumn. Maximum duration was 11.17 min for a dive to 237+ m in winter. New Zealand fur seals are the deepest diving fur seal species reported thus far. The estimated theoretical aerobic dive limit was exceeded on 18.4% of dives (range of individual values 0.2-57.8%). Females (n = 12) were ashore about 1.8 days at a time during February through November, and this increased to about 4.3 days during December and January. Average time spent away from the rookery ranged from 3 to 15 days.

Tourist Disturbance On New Zealand Fur Seals (Arctophalus Forsteri)

2002 ◽  
Vol 24 (1) ◽  
pp. 85 ◽  
Author(s):  
LJ Boren ◽  
NJ Gemmell ◽  
KJ Barton
Keyword(s):  
New Zealand ◽  
Marine Mammals ◽  
Effective Management ◽  
Negative Effects ◽  
Management Guidelines ◽  
Tourist Attractions ◽  
Fur Seals ◽  
Fur Seal ◽  
Current Minimum ◽  
The Impact

Marine mammals are significant tourist attractions around New Zealand, however, the impact of eco-tourism on these species is poorly documented. Effective management to mitigate any negative effects requires an understanding of target species? reactions to tourist activities. We have studied the effects of tourist activities on New Zealand fur seals (Arctocephalus forsteri) using a novel combination of observations and controlled approaches. Three study areas were selected reflecting a range of visitor density, type of tourism, and the anticipated sensitivity of fur seals to disturbance. Behaviour was observed using instantaneous scan sampling and attributes of tourist approaches were tested experimentally by controlled approaches. Approaches were made on land, by kayak, and motorboat. Fur seal responses and the distance at which the seal responded were recorded. Our results indicate that A. forsteri behaviour was being modified by tourist activities. Habituation was occurring at study areas with high levels of tourist activity. Approachers following current minimum approach distances still caused some animals to modify their behaviour and new minimum approach distances are recommended based on controlled approaches to seals at all study areas. Our work demonstrated that controlled approaches can be a useful tool to develop effective management guidelines to lessen impacts from eco-tourism activities.

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