|Scientific Name:||Arctocephalus forsteri|
|Species Authority:||(Lesson, 1828)|
Arctocephalus australis subspecies forsteri (Lesson, 1828)
Arctophoca australis subspecies forsteri (Lesson, 1828)
|Taxonomic Notes:||In 2011 the genus of all Fur Seals other than Arctocephalus pusillus was changed from Arctocephalus to Arctophoca, Peters 1866 (Committee on Taxonomy 2011) based on evidence presented in Berta and Churchill (2012). However, in 2013, based on genetic evidence presented in Nyakatura and Bininda-Emonds (2012), this change was considered to be premature and these species were returned to the genus Arctocephalus pending further research (Committee on Taxonomy 2013).
This species was formerly referred to Arctocephalus doriferus in Australia (King 1969). Small genetic differences, but no morphological differences, between the Australian and New Zealand populations have been reported (Lento et al. 1994, Rice 1998).
The traditional common name for this species, New Zealand Fur Seal, is problematic because most of the current population lives in Australia, not New Zealand. A new, more appropriately descriptive common name, Long-nosed Fur Seal, has been proposed for the Australian population (Shaughnessy and Goldsworthy 2014).
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Chilvers, B.L. & Goldsworthy, S.D.|
|Facilitator/Compiler(s):||Lowry, L., Battistoni, A., Ahonen, H. & Chiozza, F.|
Presently the majority of New Zealand Fur Seal populations are increasing, and there is no evidence for sustained declines anywhere within their range. The breeding range of the species is still expanding in both New Zealand and Australia. Although the species is subject to some commercial fisheries bycatch in both New Zealand and Australia, those takes do not appear to be inhibiting broad scale population recovery. The species is therefore assessed as Least Concern.
|Range Description:||In New Zealand, this species occurs around both the North and South Islands, with newly formed breeding colonies now established on the North Island (Bouma et al. 2008) and established and predominantly expanding breeding colonies around the entire South Island (Boren et al. 2006a). There are well established and expanding colonies also found on Stewart Island and all of New Zealand's sub-Antarctic islands. In Australia, the species occurs in the coastal waters and on the offshore islands of South and Western Australia, from just east of Kangaroo Island west to the southwest corner of the continent, and also in southern Tasmania. Small populations are establishing in Bass Strait and Victorian and southern New South Wales coastal waters (Kirkwood and Goldsworthy 2013).
The range of New Zealand Fur Seals extends south to Australia’s Macquarie Island, where males mate with Antarctic and Subantarctic Fur Seals and produce hybrid pups (Lancaster et al. 2006). Vagrants have been recorded in New Caledonia and a bone was found in a 14th century archaeological site in the Cook Islands.
Native:Australia (Macquarie Is., South Australia, Western Australia); New Zealand (North Is., South Is.)
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
Before human arrival, New Zealand Fur Seals bred around all the New Zealand mainland and subantarctic islands. Maori subsistence hunting reduced their range in New Zealand and commercial sealing in the 1700s and 1800s took seal numbers to near extinction with over 930,000 skins known to have been exported from New Zealand and Australian harbours. Currently, populations are increasing in both Australia and New Zealand (Brothers and Pemberton 1990, Shaughnessy and Gales 1990, Shaughnessy and Goldsworthy 2007, Boren et al. 2006a, Bouma et al. 2008, Shaughnessy et al. 2014).
In 2005-2006, New Zealand Fur Seal pup production at the 40 known Australian breeding colonies was estimated at 17,600 pups, equivalent to approximately 35,000 breeding females. For New Zealand, the largest breeding colony is at Bounty’s Island, last surveyed in 1980 with 4,380 pups born “and increasing” (Taylor 1996).
Apart from a few colonies like Open Bay Islands that are in decline, the overall trend throughout New Zealand is for an increasing population but there are no comprehensive data available for a total population estimate.
At 28 breeding sites surveyed in South Australia in 2013/14, 20,426 pups were recorded, with most on Kangaroo Island (10,133 pups) and the Neptune and Liguanea Islands off the southern Eyre Peninsula (9,711 pups; Shaughnessy et al. 2014). At 17 breeding sites off the southern coast of Western Australia, 3,518 pups were recorded in 2011/12 (Campbell et al. 2014). At four breeding sites in Victoria, 276 pups have been recorded; at four breeding sites in southern Tasmania, 399 pups have been recorded and at one site in southern New South Wales 36 pups have been recorded. The maximum pup numbers recorded between 2008/09 and 2013/14 across all sites in Australia is 24,656. South Australia (83%) and Western Australia (14%) have the bulk of Australia’s New Zealand Fur Seal population. Based on a pup to total population multiplier of 4.76 (Goldsworthy and Page 2007) the Australian segment of the population is currently estimated to number ~ 117,400.
Between the 1989/90 and the 2013/14 breeding season, the Fur Seal population in South Australia has increased 3.6 fold, with the average annual increase in pup production being 5.3% (Shaughnessy et al. 2014). However, rates of increase at some sites have been much greater. For example, in the Cape Gantheaume Wilderness Protection Area on Kangaroo Island, annual monitoring of pup production demonstrates a remarkable recovery over a 26 year period from 1988/89 (457 pups) to 2013/14 (5,333 pups), an 11.7 fold increase at an average rate of 10% per year (Goldsworthy et al. 2014). In contrast, pup production at the Neptune and Liguanea Islands appears to have peaked in the mid-2000s, with most of the available breeding habitat now full (Shaughnessy et al. 2014). The centre of population expansion in Australia in now on Kangaroo Island. The growth of New Zealand Fur Seal populations since the 1970 and 1980s in Australia is attributable to recovery from 19th century sealing (1800-1830) and subsequent take.
Overall, the total population of New Zealand Fur Seals across both New Zealand and Australia is estimated to be approximately 200,000.
|Habitat and Ecology:||
New Zealand Fur Seals are sexually dimorphic, with adult males reaching twice the length and more than 2.1 times the weight of adult females. In South Australia, females reach 95% of their mean asymptotic length (137 cm) and mass (48.8 kg) by 7 and 12 years, respectively. Males reach 95% of their mean asymptotic length (170 cm) and mass (104.3 kg) by 10 and 12 years, respectively (McKenzie et al. 2007). The largest males weighed in South Australia and at the Open Bay Islands of New Zealand, were 147 kg (187 cm length, 13.5 years old), and 154 kg, respectively. Pups at birth weigh 3-4 kg and are 40-55 cm long. Males double their mass in 60–100 days and females in 80–90 days, and weigh 13–16 kg at weaning which occurs when they are 9-10 months old (Goldsworthy 2006). Pups moult into adult pelage at 3-4 months. Females become mature at 4-6 years of age, males at 8-10 years (Dickie and Dawson 2003; McKenzie et al. 2005, 2007). Generation time is 9.9 years (Wickens and York 1997).
New Zealand Fur Seals are polygynous. Males arrive at colonies in late October before females and acquire and defend territories with vocalizations, ritualized displays, and fighting. Male territories include an average of 5-8 females with the ratio of females to males varying between different colonies. The number of animals ashore at rookeries declines rapidly in January. Male vocalizations include a bark or whimper, a guttural threat, a low-intensity threat, a full threat, and a submissive call. Females growl and have a pup-attraction call that is a high-pitched wail (Crawley and Wilson 1976, Ling 1987).
Pups are born from mid-November to January, with most born in December. Oestrous occurs 7-8 days after a female gives birth, and they usually spend another 1-2 days ashore with their pup before departing and beginning a cycle of foraging trips and periods of pup attendance ashore (Goldsworthy and Shaughnessy 1994, Goldsworthy 2006). Shore attendance bouts (when pups are nursed) last ~1.7 days while foraging trips to sea increase in duration from ~3-5 days in early lactation, to 8-11 days late in lactation. However, foraging trips lasting more than 20 days are not uncommon (Goldsworthy 2006).
New Zealand Fur Seals are considered non-migratory. At sea they actively groom and raft in a variety of postures typical of southern fur seals including the “jug handle” position while sleeping at the surface. They often “porpoise” out of the water when travelling rapidly at sea. Rocky shoreline habitat with shelter, and locations more exposed to wind and weather, are preferred for haul-outs and rookeries. When hauled out in New Zealand they readily enter areas of coastal vegetation behind the shoreline (Crawley and Wilson 1976, Ryan et al. 1997).
New Zealand Fur Seals prey on a large variety of cephalopods, fishes, and birds (Fea et al. 1999, Goldsworthy et al. 2003, Lalas and Webster 2014). In South Australia, key cephalopod prey include Southern Ocean Arrow Squid and Gould’s Squid; key fish species include Redbait, Ocean Jackets, Swallowtail, and myctophids; and the most frequently taken bird species are Little Penguins and Short-Tailed Shearwaters (Page et al. 2005a). Satellite tracking studies in South Australia indicate marked spatial separation in foraging regions used by juvenile, adult female, and adult male seals. In early lactation (December to March), adult females undertake short foraging trips to mid-outer shelf waters (70-90 km from the colony), in regions associated with localized upwelling (Page et al. 2006, Baylis et al. 2008a). However, in April and May most females switch to foraging in distant oceanic waters associated with the Subtropical Front, 700-1,000 km to the south of breeding colonies, and continue foraging in these waters up until the weaning of their pups in September/October (Baylis et al. 2008a,b; Baylis et al. 2012). In contrast, adult males focus their foraging over the continental slope. Juvenile seals forage in oceanic waters where they target nocturnal surface-migrating myctophid fish (Baylis et al. 2005). Adult female and male seals both forage in the water column in relative shallow depths and near or on the bottom in deeper water. For females, benthic dives on the continental shelf in South Australia are typically to 60-80 m, while those of males on the continental slope are 100-200 m. The maximum dive durations and depths recorded for adult females are 9.3 min and 312 m, and 14.8 min and 380 m for males (Page et al. 2005b).
Predators include Killer Whales, Sharks, male New Zealand Sea Lions and possibly Leopard Seals at sub-Antarctic islands (Shaughnessy 2006).
|Use and Trade:||Humans in both Australia and New Zealand have likely harvested New Zealand Fur Seals for subsistence since first contact. The species is currently protected by law in both Australia and New Zealand and currently there is no use or trade. New Zealand Fur Seals are listed on CITES Appendix II.|
Humans in both Australia and New Zealand have likely harvested New Zealand Fur Seals for subsistence since first contact. There is evidence that Polynesian colonization of New Zealand and harvest of seals led to declines and loss of colonies on the coast of the North Island. European sealers nearly exterminated the species in the 19th century (Crawley and Wilson 1976), but due to protection it has rebounded to occupy most of its former range.
Trawl and other fisheries are a source of entanglement and drowning for Fur Seals (Page et al. 2004, Thompson and Abraham 2010, Shaughnessy et al. 2003). Tourism and disturbance at colonies can lead to disruption of breeding behaviour and site abandonment, although most colonies are on offshore islands and are relatively inaccessible. Marine debris entanglement is also known to be an increasing problem (Page et al. 2004, Boren et al. 2006b).
Like all fur seals, New Zealand Fur Seals are vulnerable to oil spills because of their dependence on their thick pelage for thermoregulation (Gales 1991). They share most of their range with several other regularly occurring pinniped species and they also come in close contact with domestic and feral animals and in some areas wild carnivores. Thus, they are at risk from transmission of infectious diseases such as morbilliviruses, brucellosis, leptospirosis, and tuberculosis (MacKereth et al. 2005).
This species is protected by law in both Australia and New Zealand. In New Zealand all marine mammals are protected by the Marine Mammals Protection Act of 1978. The New Zealand Fur Seal was listed as a Least Concerned for New Zealand Species in 2010 under the New Zealand threat classification system (Baker et al. 2010, Townsend et al. 2008).
In Australia, State Governments have jurisdiction over marine mammals within 4.8 km of the coast and each state has its own conservation legislation. The Australian Commonwealth Government has jurisdiction from 4.8 km offshore throughout the rest of the country’s 322 km Exclusive Economic Zone. Under the Australian Environment Protection and Biodiversity Conservation Act 1999, New Zealand Fur Seals are listed as protected marine species. An action plan for conservation of Australian seals was published in 1999 (Shaughnessy 1999). New Zealand Fur Seals are listed on CITES Appendix II.
|Citation:||Chilvers, B.L. & Goldsworthy, S.D. 2015. Arctocephalus forsteri. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 05 July 2015.|