|Scientific Name:||Arctocephalus gazella|
|Species Authority:||(Peters, 1875)|
|Taxonomic Notes:||Antarctic Fur Seals were formerly considered a subspecies of Arctocephalus tropicalis and were known as A. t. gazella (Repenning et al. 1971).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||Aurioles, D. & Trillmich, F. (IUCN SSC Pinniped Specialist Group)|
|Reviewer/s:||Kovacs, K. & Lowry, L. (Pinniped Red List Authority)|
Due to its large and apparently increasing population size, the Antarctic Fur Seal should remain classified as Least Concern.
IUCN Evaluation of the Antarctic Fur Seal, Arctocephalus gazella
Prepared by the Pinniped Specialist Group
A. Population reduction Declines measured over the longer of 10 years or 3 generations
A1 CR > 90%; EN > 70%; VU > 50%
Al. Population reduction observed, estimated, inferred, or suspected in the past where the causes of the reduction are clearly reversible AND understood AND have ceased, based on and specifying any of the following:
(a) direct observation
(b) an index of abundance appropriate to the taxon
(c) a decline in area of occupancy (AOO), extent of occurrence (EOO) and/or habitat quality
(d) actual or potential levels of exploitation
(e) effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
All subpopulations of Antarctic Fur Seals are currently either increasing or stable.
A2, A3 & A4 CR > 80%; EN > 50%; VU > 30%
A2. Population reduction observed, estimated, inferred, or suspected in the past where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
All subpopulations of Antarctic Fur Seals are currently either increasing or stable.
A3. Population reduction projected or suspected to be met in the future (up to a maximum of 100 years) based on (b) to (e) under A1.
A population reduction of Antarctic Fur Seals is not expected in the future. It is possible, however, that global climate change may alter environmental conditions to the detriment of this species.
A4. An observed, estimated, inferred, projected or suspected population reduction (up to a maximum of 100 years) where the time period must include both the past and the future, and where the causes of reduction may not have ceased OR may not be understood OR may not be reversible, based on (a) to (e) under A1.
All subpopulations of Antarctic Fur Seals are currently either increasing or stable. While a population reduction is not expected in the future, it is possible that global climate change may alter environmental conditions to the detriment of this species.
B. Geographic range in the form of either B1 (extent of occurrence) AND/OR B2 (area of occupancy)
B1. Extent of occurrence (EOO): CR < 100 km²; EN < 5,000 km²; VU < 20,000 km²
The EOO of Antarctic fur seals is > 20,000 km².
B2. Area of occupancy (AOO): CR < 10 km²; EN < 500 km²; VU < 2,000 km²
The AOO of Antarctic fur seals is > 2,000 km².
AND at least 2 of the following:
(a) Severely fragmented, OR number of locations: CR = 1; EN < 5; VU < 10
(b) Continuing decline in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) area, extent and/or quality of habitat; (iv) number of locations or subpopulations; (v) number of mature individuals.
(c) Extreme fluctuations in any of: (i) extent of occurrence; (ii) area of occupancy; (iii) number of locations or subpopulations; (iv) number of mature individuals.
Subpopulations are not severely fragmented and the number of breeding locations is > 10. The species is not experiencing continuing decline or extreme fluctuations in extent of occurrence, area of occupancy, number of subpopulations, number of mature individuals or area, extent or quality of habitat.
C. Small population size and decline
Number of mature individuals: CR < 250; EN < 2,500; VU < 10,000
AND either C1 or C2:
C1. An estimated continuing decline of at least: CR = 25% in 3 years or 1 generation; EN = 20% in 5 years or 2 generations; VU = 10% in 10 years or 3 generations (up to a max. of 100 years in future)
C2. A continuing decline AND (a) and/or (b):
(a i) Number of mature individuals in each subpopulation: CR < 50; EN < 250; VU < 1,000
(a ii) % individuals in one subpopulation: CR = 90–100%; EN = 95–100%; VU = 100%
(b) Extreme fluctuations in the number of mature individuals.
The current abundance of Antarctic fur seals is well in excess of 10,000. The number of mature individuals in 9 of 11 subpopulations is estimated to be over 1,000. Approximately 90% of individuals belong to the South Georgia subpopulation.
D. Very small or restricted population
Number of mature individuals: CR < 50; EN < 250; VU < 1,000 AND/OR restricted area of occupancy typically: AOO < 20 km² or number of locations < 5
The current abundance of mature Antarctic fur seals is well in excess of 1,000, the AOO is far larger than 20 km² and the number of locations is > 5.
E. Quantitative analysis
Indicating the probability of extinction in the wild to be: Indicating the probability of extinction in the wild to be: CR > 50% in 10 years or 3 generations (100 years max.); EN > 20% in 20 years or 5 generations (100 years max.); VU > 10% in 100 years
There has been no quantitative analysis of the probability of extinction of Antarctic Fur Seals.
Listing recommendation — Estimates indicate an Antarctic Fur Seal abundance of several million individuals breeding at numerous sites on 11 islands or island groups. While over 90% of Antarctic fur seals breed on the island of South Georgia, eight other subpopulations are estimated to contain more than a 1,000 adults. All subpopulations are either stable or increasing. No major threats currently affect any subpopulations and it is unlikely that any will do so in the near future. This being said, Antarctic Fur Seals may be affected by global climate change if their prey species are effected by changes in the environment. It should also be noted that Antarctic Fur Seals experienced a severe population bottleneck during the 19th and 20th Centuries that has reduced their genetic variation and which may render this species vulnerable to disease or climate change. Under present conditions Antarctic fur seals qualify for listing in the category Least Concern.
|Range Description:||Antarctic Fur Seals are widely-distributed in waters south, and in some areas slightly north, of the Antarctic Convergence (Bonner 1968). While most Antarctic Fur Seal 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. 2006), Îles Crozet (Guinet et al. 1994), Îles Kerguelen (Guinet et al. 2000), Heard Island (Page et al. 2003), McDonald Island (Johnston 1982), Macquarie Island (Goldsworthy et al. 1999) and Bouvetøya (Hofmeyr et al. 2005). Vagrants have been recorded at Gough Island (Wilson et al. 2006) and on the coasts of Antarctica (Shaughnessy and Burton 1986), southern South America (Drehmer and De Oliviera 2000) and Australia (Stewardson 2007). Antarctic Fur Seals disperse widely when at sea. Distribution and movements are, however, not well known (Boyd et al. 1998).|
Native:Bouvet Island; French Southern Territories (Crozet Is., Kerguelen); Heard Island and McDonald Islands; South Georgia and the South Sandwich Islands (South Georgia, South Sandwich Is.)
Vagrant:Antarctica; Argentina; Australia (Macquarie Is. - Native); Brazil; Chile (Juan Fernández Is. - Native); Saint Helena, Ascension and Tristan da Cunha (Tristan da Cunha); South Africa (Marion-Prince Edward Is. - Native)
|FAO Marine Fishing Areas:||
Atlantic – Antarctic; Atlantic – southwest; Indian Ocean – Antarctic; Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The island of South Georgia supports approximately 95% of all Antarctic Fur Seals. The total population of this site in 1999/2000 was estimated to be between 4.5 and 6.2 million and is believed to have increased by between 6 and 14 % since the 1990/91 season (Boyd pers. comm. in SCAR EGS 2004). The second largest population, at Bouvetøya supported some 66,000 individuals in the 2001/02 season (Hofmeyr et al. 2005). Other populations range in size from a few hundred to a few thousand (SCAR EGS 2004). All populations are believed to be either increasing or stable (SCAR EGS 2004).|
|Habitat and Ecology:||
Antarctic Fur Seals are a strongly sexually dimorphic species. Adult males are approximately 1.8 m long and weigh between 130 and 2,000 kg. Adult females are 1.2 - 1.4 m and 22 - 50 kg. Newborns weigh 6 - 7 kg (Laws 1993). Age of first reproduction is 3 years for females (Lunn et al. 1994) and 7 years for males (McCann and Doidge 1987).
Antarctic Fur Seals are highly polygynous. Males arrive at the colonies in late October, some 2-3 weeks before the first females arrive and establish territories. Males continue to arrive and challenge one another for territories through much of 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. They give birth 1-2 days after arrival at the colony and subsequently attend their pup for 6-7 days. They come into oestrous, mate and then depart shortly afterwards for their first foraging trip of the season (Doidge et al. 1986, Payne 1977). Foraging trip and attendance periods vary by year depending on the availability of the lactating female’s chief prey, adult krill, but generally last 4-5 days at sea followed by 2-3 days attendance on shore (Boyd 1999, Costa et al. 1989, Guinet et al. 2000). Antarctic fur seals undertake short shallow dives, primarily at night (Boyd and Croxall 1992, Costa et al. 2000, Robinson et al. 2002). Mean dive depth and duration increase during the lactation period (Boyd 1999, Costa et al. 1989, Guinet et al. 2000).
Pups are weaned at about four months of age. After the pups are weaned, females are thought to disperse widely and are seldom seen at the colonies before the next breeding season. Breeding bulls also depart the rookery, but subadults and some adult males can be seen at rookeries on South Georgia all year (Bonner 1968, Payne 1977).
The diet of Antarctic Fur Seals varies by season and location. At South Georgia and Bouvet Island Antarctic Fur Seals feed primarily on krill (Bonner 1968, Klages et al. 1998, North et al. 1983). At Heard Island, Macquarie Island and the Prince Edward Islands krill is not available and lactating females prey primarily on cephalopods and fish such as myctophids and notothenids (Green et al. 1989, Green et al. 1991, Klages and Bester 1998, Robinson et al. 2002). 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. 2006) and the Îles Crozet (Guinet et al. 1994) and with both Subantarctic Fur Seals and New Zealand Fur Seals at Macquarie Island (Goldsworthy et al. 1999).
Commercial sealing drove this species to the brink of extinction by the late 19th century. It is now believed that this species survived this period of over-exploitation in very small numbers at three sites: South Georgia, Bouvetøya and the Îles Kerguelen (Hofmeyr et al. 2005, Wynen et al. 2000). The species has probably lost considerable genetic diversity due to the historical population bottleneck (Wynen et al. 2000) and may now be at increased risk from disease outbreaks and environmental change.
Waters inhabited by Antarctic Fur Seals are exploited by few fisheries, but these may expand in the future (Hanchet et al. 2003). This species has been recorded entangled in marine debris such as discarded fishing line, nets, packing bands and other objects. The numbers of Antarctic Fur Seals entangled in anthropogenic debris annually has been estimated to be as high as 1% of the total population. The majority of entangled animals are juvenile and subadult seals. In approximately 30% of cases recorded, the debris caused injury. Most entangled seals are expected to die as a result of their entanglement (Bonner and McCann 1982, Croxall et al. 1990).
Leopard Seals have been noted to take as many as a third of pups born at sites in the South Shetland Islands (Hiruki et al. 1989). Levels of predation may be high enough to cause a population decline at this site (Boveng et al. 1998).
The risk of transfer of diseases, such as morbillivirus from other pinnipeds or terrestrial animals to Antarctic Fur Seals is unknown. Antarctic fur seals are considered to be one of several pinnipeds at high risk of future disease outbreaks because of their rapidly expanding population, tendency for most animals to congregate in large dense aggregations, and effect of environmental changes associated with global warming on the spread of diseases (Lavigne and Schmitz 1990). Tourism takes place at several locations, but due to the isolation of haulout sites, visits by tourists are rare (Kirkwood et al. 2003)
The effect of global climate change on Antarctic Fur Seals is unknown, but it has been suggested that warming may result in population declines (Learmonth et al. 2006).
|Conservation Actions:||The Antarctic Treaty and the Convention for the Conservation of Antarctic Seals protect 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 (Malvinas) 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 and also by the South African Seabirds and Seals Protection Act (PEIMC 1996). It is listed on CITES Appendix II.|
|Citation:||Aurioles, D. & Trillmich, F. (IUCN SSC Pinniped Specialist Group) 2008. Arctocephalus gazella. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 09 March 2014.|
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