Hydrurga leptonyx (de Blainville, 1820)
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publication ID |
https://doi.org/ 10.5281/zenodo.6607185 |
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DOI |
https://doi.org/10.5281/zenodo.6607216 |
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persistent identifier |
https://treatment.plazi.org/id/464F694F-FFAC-A851-FFB8-D7FE91F7FDE0 |
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treatment provided by |
Diego |
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scientific name |
Hydrurga leptonyx |
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Leopard Seal
French: Phoque |éopard / German: Seeleopard / Spanish: Foca leopardo
Other common names: Sea Leopard
Taxonomy. Phoca leptonyx de Blainville, 1820 View in CoL ,
“des environs des iles Falckland ou Malouines” (= Falkland Islands, UK) .
This species is monotypic.
Distribution. Antarctic and subantarctic cold waters between 50° S and 80° S. View Figure
Descriptive notes. Total length 250-320 cm (males) and 241-338 cm (females); weight 200-455 kg (males) and c.225-590 kg (females). Newborns are c.120 cm in length and weigh ¢.30 kg.
Female Leopard Seals tend to be larger than males. Leopard Seals have narrow but still relatively massive heads, with wide and long gapes, robust canine and post-canine teeth, and powerful jaws. Torso is robust, foreflippers long and powerfully propulsive, and rest of body quickly tapering and slim. Pelage is dark gray dorsally with scattered spots and blotches, and countershaded ventrum is silver and heavily spotted.
Habitat. Primarily pack-ice habitats in Antarctic waters. Leopard Seals appear to be mostly solitary and, although widespread, are not particularly abundant.
Food and Feeding. Leopard Seals have a very diverse diet that changes with seasonal and local abundance of prey. Most prey is caught in the water. Leopard Seals feed on fish, cephalopods,krill, and even warm-blooded prey such as Subantarctic Fur Seals ( Arctocephalus tropicalis ), Antarctic Fur Seals ( Arctocephalus gazella), Australian Sea Lions ( Neophoca cinerea), New Zealand Sea Lion ( Phocarctos hookeri), Crabeater Seals ( Lobodon carcinophaga ), Ross Seals ( Ommatophoca rossii ), and Southern Elephant Seal ( Mirounga leonina ), with a focus on young Crabeater Seals and Weddell Seals ( Leptonychotes weddellit). Leopard Seals are known to prey on penguins ( Spheniscidae ). From mid-October to mid-February (summer) in Prydz Bay, Antarctica, male and female Leopards Seals used five different hunting styles to prey on a seasonally available breeding colony of Adelie penguins ( Pygoscelis adeliae): patrolling fast-ice edges (c.47% of 32 observations of five Leopard Seals) and ambushing from between ice floes (c.41%), both highly correlated with locations of large numbers of departing and arriving Adelie penguins; searching around ice floes (c.6%); stalking under thin ice (c.3%); and searching in open water (c.3%). Near a haul-out site on Bird Island, South Georgia, Gentoo penguins ( Pygoscelis papua) were most common in winter diets of Leopard Seals, and macaroni penguins ( Eudyptes chrysolopus) were most common in summer diets. At the same location between 1983 and 1995, subadult Antarctic Fur Seals (58%) and macaroni penguins (27-8%) were the main prey of Leopard Seals; other prey included Gentoo penguins (8:6%), young Southern Elephant Seals ¢.150-200 cm in length (31%), diving petrel (Pelecanoides spp., 19%), and Cape petrel (Daption capense, 0-6%).
Breeding. Little is known about the Leopard Seal’s breeding system, but most observations of newborns have been in November and early December in pack-ice habitats, with weaning c.3—4 weeks later. Mating is thought to take place in the water after offspring are weaned and females resume feeding. Male Leopard Seals become sexually mature at c.3-6 years old and females at 2-7 years old. Longevity is estimated to be more than 26 years.
Activity patterns. Leopard Seals are not often seen hauled out on ice or land and evidently spend most of their time in the water hunting and foraging. At Freshwater Beach on Bird Island, South Georgia, Leopards Seals haul-out and sleep on the beach and on nearby ice floes and icebergs during winter (April-November); they also sleep in the middle of kelp beds with their heads well above the water.
Movements, Home range and Social organization. Recentsatellite tracking of Leopard Seals suggests that they move north as sea ice forms and expands in autumn and winter and then move south again toward the Antarctic continent as sea ice melts and recedes in spring and summer. Small numbers of Leopard Seals have been regularly recorded as transients from coasts of New Zealand, Tasmania, Australia, South America, and South Africa. Seasonally resident and vagrant seals have also been regularly observed on many subantarctic islands including Marion Island, Kerguelen Island, Heard Island, Macquarie Island, South Georgia, South Orkney Islands, Falkland Islands (= Malvinas), Juan Fernandez Islands, and Easter Island. The most northerly records reported for Leopard Seals have been in the western South Pacific Ocean at the Cook Islands ofsingle juveniles in June 1956 and July 1960, the eastern South Pacific Ocean on Easter Island and Chilean coast at Punto Choros, and the western South Atlantic Ocean at Rio de Janeiro, Brazil. An extremely isolated sighting of a ten-month-old Leopard Seal in the central South Pacific Ocean in August 2013 corresponded with a new record for annual coverage of winter sea ice in the Southern Ocean.
Status and Conservation. Classified as Least Concern on The IUCN Red List. 1.eopard Seals have never been substantially hunted although early Antarctic explorers did kill small numbers for food and to feed sled dogs, and a brief experimental harvest by Soviet sealers killed ¢.650 individuals in 1986-1987. Leopard Seals are protected from harvesting by the Convention for the Conservation of Antarctic Seals. Leopard Seals are widespread and, similar to the other Antarctic seals that inhabit pack ice, population assessments are very difficult and expensive to conduct and therefore infrequently undertaken. Published global population estimates range from 100,000-300,000 individuals to 220,000-440,000 individuals.
Bibliography. Acevedo & Martinez (2013), Aguayo-Lobo et al. (2011), Bengtson et al. (2011), Forcada et al. (2012), Kooyman (1981a), Reeves, Stewart, Clapham & Powell (2002), Reeves, Stewart & Leatherwood (1992), Rodriguez et al. (2003), Rogers & Bryden (1995, 1997), Rogers, Ciaglia et al. (2013), Rogers, Hogg & Irvine (2005), Siniff & Stone (1985), Southwell, Bengtson et al. (2012), Southwell, Paxton et al. (2008), Stewart & Grove (2014), Thomas et al. (1983), Walker et al. (1998).
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