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| Subspecies: | Unknown |
|---|---|
| Est. World Population: | 700000-1000000 |
| CITES Status: | NOT LISTED |
| IUCN Status: | Least Concern |
| U.S. ESA Status: | NOT LISTED |
| Body Length: | |
| Tail Length: | |
| Shoulder Height: | |
| Weight: | |
| Top Speed: | |
| Jumping Ability: | (Horizontal) |
| Life Span: | in the Wild |
| Life Span: | in Captivity |
| Sexual Maturity: | (Females) |
| Sexual Maturity: | (Males) |
| Litter Size: | |
| Gestation Period: | |
Habitat:
Antarctic Fur Seals are a sexually dimorphic species. Adult males are approximately 1.8 m long and weigh between 130 and 200 kg. Adult females are 1.2-1.4 m and 22-50 kg. Newborns weigh six to seven kilograms (Laws 1993). Age of first reproduction is three years for females (Lunn et al. 1994) and seven years for males (McCann and Doidge 1987).
Antarctic Fur Seals are highly polygynous. The first adult males arrive at their colonies in late October, some two to three weeks before the first adult females. Males continue to arrive and challenge one another for territories throughout the season. Territories are acquired and held by use of vocalizations, threat postures, and fighting (Bonner 1968). Females begin to arrive in mid-November and most pupping and breeding occurs from late November to late December. Adult females give birth one to two days after arrival at the colony and subsequently attend their pup for six to seven days. They come into oestrous, mate and then depart shortly afterwards on their first foraging trip of the season (Payne 1977, Doidge et al. 1986). Foraging trip and attendance periods vary inter-annually depending on the availability of the lactating female’s prey, but generally last four to five days at sea followed by two to three days attendance on shore (Costa et al. 1989, Boyd 1999, Guinet et al. 2000, Kirkman et al. 2003). Antarctic Fur Seals undertake short shallow dives, primarily at night (Boyd and Croxall 1992, Costa et al. 2000, Robinson et al. 2002, Goldsworthy et al. 2010). Mean dive depth and duration increase during the lactation period (Costa et al. 1989, Boyd 1999, Guinet et al. 2000). The maximum diving depth recorded for lactating females is 181 m (Boyd and Croxall 1992).
Pups are weaned at about four months of age. After the pups are weaned, seals are thought to disperse widely and are seldom seen at the colonies before the next breeding season (Kerley 1983, Boyd et al. 1998, Warren et al. 2006). Breeding bulls also depart the rookery, but subadults and some adult males can be seen at rookeries at all times of the year (Bonner 1968, Payne 1977, Kerley 1983, Boyd et al. 1998).
The diet of Antarctic Fur Seals varies by season and locality. At South Georgia and other islands of the Scotia Arc, and at Bouvetøya, they feed primarily on Krill (Kirkman et al. 2000, Staniland and Pond 2005, Hofmeyr et al. 2010, Polito and Goebel 2010). At Heard Island, Macquarie Island, the Îles Crozet and the Prince Edward Islands, Krill is not as abundant and Antarctic Fur Seals prey primarily on cephalopods and fish such as myctophids and notothenids (Lea et al. 2002, Robinson et al. 2002, Casper et al. 2007, Cherel et al. 2007, Cherel et al. 2008, Makhado et al. 2008, Kernaléguen et al. 2012). Antarctic Fur Seals have also been known to eat Penguins at a number of sites (Bonner 1968, Green et al. 1989, Hofmeyr and Bester 1993).
Antarctic Fur Seals are sympatric with other species of Fur Seals at three sites. Hybridization with Subantarctic Fur Seals occurs at the Prince Edward Islands (Hofmeyr et al. 2006a) and the Îles Crozet (Kingston and Gwilliam 2007) and with both Subantarctic Fur Seals and New Zealand Fur Seals at Macquarie Island (Lancaster et al. 2006, Goldsworthy et al. 2010, Lancaster et al. 2010). Levels of hybridization are low at the Prince Edward Islands (Hofmeyr et al. 2006a) and at Îles Crozet (Kingston and Gwilliam 2007) and thus do not affect the integrity of this species. The population at Macquarie Island comprises 0.02% of the species total population (Goldsworthy et al. 2009).
Antarctic Fur Seals are highly polygynous. The first adult males arrive at their colonies in late October, some two to three weeks before the first adult females. Males continue to arrive and challenge one another for territories throughout the season. Territories are acquired and held by use of vocalizations, threat postures, and fighting (Bonner 1968). Females begin to arrive in mid-November and most pupping and breeding occurs from late November to late December. Adult females give birth one to two days after arrival at the colony and subsequently attend their pup for six to seven days. They come into oestrous, mate and then depart shortly afterwards on their first foraging trip of the season (Payne 1977, Doidge et al. 1986). Foraging trip and attendance periods vary inter-annually depending on the availability of the lactating female’s prey, but generally last four to five days at sea followed by two to three days attendance on shore (Costa et al. 1989, Boyd 1999, Guinet et al. 2000, Kirkman et al. 2003). Antarctic Fur Seals undertake short shallow dives, primarily at night (Boyd and Croxall 1992, Costa et al. 2000, Robinson et al. 2002, Goldsworthy et al. 2010). Mean dive depth and duration increase during the lactation period (Costa et al. 1989, Boyd 1999, Guinet et al. 2000). The maximum diving depth recorded for lactating females is 181 m (Boyd and Croxall 1992).
Pups are weaned at about four months of age. After the pups are weaned, seals are thought to disperse widely and are seldom seen at the colonies before the next breeding season (Kerley 1983, Boyd et al. 1998, Warren et al. 2006). Breeding bulls also depart the rookery, but subadults and some adult males can be seen at rookeries at all times of the year (Bonner 1968, Payne 1977, Kerley 1983, Boyd et al. 1998).
The diet of Antarctic Fur Seals varies by season and locality. At South Georgia and other islands of the Scotia Arc, and at Bouvetøya, they feed primarily on Krill (Kirkman et al. 2000, Staniland and Pond 2005, Hofmeyr et al. 2010, Polito and Goebel 2010). At Heard Island, Macquarie Island, the Îles Crozet and the Prince Edward Islands, Krill is not as abundant and Antarctic Fur Seals prey primarily on cephalopods and fish such as myctophids and notothenids (Lea et al. 2002, Robinson et al. 2002, Casper et al. 2007, Cherel et al. 2007, Cherel et al. 2008, Makhado et al. 2008, Kernaléguen et al. 2012). Antarctic Fur Seals have also been known to eat Penguins at a number of sites (Bonner 1968, Green et al. 1989, Hofmeyr and Bester 1993).
Antarctic Fur Seals are sympatric with other species of Fur Seals at three sites. Hybridization with Subantarctic Fur Seals occurs at the Prince Edward Islands (Hofmeyr et al. 2006a) and the Îles Crozet (Kingston and Gwilliam 2007) and with both Subantarctic Fur Seals and New Zealand Fur Seals at Macquarie Island (Lancaster et al. 2006, Goldsworthy et al. 2010, Lancaster et al. 2010). Levels of hybridization are low at the Prince Edward Islands (Hofmeyr et al. 2006a) and at Îles Crozet (Kingston and Gwilliam 2007) and thus do not affect the integrity of this species. The population at Macquarie Island comprises 0.02% of the species total population (Goldsworthy et al. 2009).
Range:
Antarctic Fur Seals inhabit the Southern Ocean and are widely-distributed in waters south, and in some areas north, of the Antarctic Convergence (Bonner 1968). While most Antarctic Fur Seals breed at South Georgia (Boyd 1993), colonies are also found on the South Shetland Islands (Goebel et al. 2003), the South Orkney Islands (Boyd 1993), the South Sandwich Islands (Holdgate 1962), the Prince Edward Islands (Bester et al. 2003, Hofmeyr et al. 2006a), Îles Crozet (Guinet et al. 1994), Îles Kerguelen (Guinet et al. 2000), Heard Island (Page et al. 2003), McDonald Island (Johnstone 1982), Macquarie Island (Goldsworthy et al. 2009) and Bouvetøya (Hofmeyr et al. 2005). Vagrants have been recorded at Gough Island (Wilson et al. 2006), Tristan da Cunha (Bester et al. 2014) and on the coasts of Antarctica (Shaughnessy and Burton 1986), southern South America (Drehmer and De Oliviera 2000), and Australia (Shaughnessy et al. 2014). Antarctic Fur Seals disperse widely when at sea (Boyd et al. 1998, Staniland et al. 2012), however few data on distribution and movements at sea have been published.
Conservation:
Antarctic Fur Seals are protected by virtue of the isolation of their marine habitat and haulout sites. The Antarctic Treaty and the Convention for the Conservation of Antarctic Seals protects populations of this species of Fur Seal below 60ºS. North of the Antarctic Treaty area, Antarctic Fur Seals are protected by the nations that govern the islands on which they breed. The Falkland Islands Dependencies Conservation Ordinance provides protection for Antarctic Fur Seals on South Georgia and the South Sandwich Islands (Reijnders et al. 1993). Seals on the Prince Edward Islands are protected by virtue of these islands status as a special nature reserve, their location within a marine protected area, and also by the South African Seabirds and Seals Protection Act (PEIMP 2010). Large reserves have also been established around Heard and McDonald islands (http://heardisland.antarctica.gov.au/protection-and-management/marine-reserve) and Macquarie Island (http://www.environment.gov.au/topics/marine/marine-reserves/south-east/macquarie-island) that serve to protect Seals.