Southern elephant seal

Southern elephant seal
Name	Southern elephant seal
Status	LC
Status system	IUCN3.1
Genus	Mirounga
Species	leonina
Authority	(Linnaeus, 1758)

Southern elephant seal The southern elephant seal is a large pinniped species noted for extreme sexual dimorphism and deep diving ability. The species is studied across research programs by institutions like British Antarctic Survey, Scott Polar Research Institute, Australian Antarctic Division, Smithsonian Institution, and Monterey Bay Aquarium Research Institute and appears in conservation frameworks such as the IUCN Red List, Convention on Migratory Species, Agreement on the Conservation of Seals in the Wadden Sea and the North Sea, Convention for the Conservation of Antarctic Seals, and national legislation in Australia, Chile, Argentina, South Africa, and United Kingdom.

Taxonomy and Evolution

The taxonomic placement of the species is in the genus Mirounga within the family Phocidae, related to taxa described by Carl Linnaeus and later revised by researchers at Natural History Museum, London, Smithsonian Institution National Museum of Natural History, and the American Museum of Natural History. Molecular phylogenetics using methods from teams at University of California, Santa Cruz, University of Cambridge, University of Oxford, and University of Melbourne link the species to fossil records found near South Georgia, Kerguelen Islands, Patagonia, Falkland Islands, and interpreted in paleontological studies at Royal Society, Palaeontological Association, and Geological Society of London. Evolutionary analyses published in journals associated with Nature, Science (journal), Proceedings of the Royal Society B, and Journal of Mammalogy indicate divergence times estimated using calibrations from Miocene deposits and comparisons with extinct pinnipeds described by researchers at University of California, Berkeley and Harvard University.

Description

Adults exhibit pronounced sexual dimorphism with male morphometrics recorded by teams from University of Tasmania, University of British Columbia, University of Cape Town, University of Buenos Aires, and McGill University. Males develop a hypertrophied proboscis used in vocal contests documented by ethologists at Max Planck Society, Smithsonian Tropical Research Institute, Royal Ontario Museum, Zoological Society of London, and Australian Museum. Measurements reported in monographs from Cambridge University Press, Oxford University Press, and papers authored by researchers at Woods Hole Oceanographic Institution show males can exceed three metric tonnes, while females average substantially less, a pattern discussed in syntheses from International Union for Conservation of Nature and Convention on International Trade in Endangered Species of Wild Fauna and Flora assessments. Pelage descriptions and moulting patterns are included in field guides produced by National Audubon Society, BirdLife International, Royal Society for the Protection of Birds, Museo Nacional de Historia Natural (Chile), and Museo Argentino de Ciencias Naturales.

Distribution and Habitat

Breeding and haul-out sites occur on subantarctic islands and southern continental shores recorded by surveys from South Georgia and the South Sandwich Islands, Macquarie Island, Kerguelen Islands, Prince Edward Islands, Falkland Islands, Heard Island and McDonald Islands, Crozet Islands, Bouvet Island, Antarctic Peninsula, Patagonia, Tierra del Fuego, and parts of South Africa and Tasmania. Satellite telemetry studies conducted by National Aeronautics and Space Administration, European Space Agency, Geoscience Australia, South African National Antarctic Programme, and British Antarctic Survey track migrations between foraging zones in the Southern Ocean, bathymetric features like the Kerguelen Plateau, Ridge, Polar Front, and frontal zones monitored by Global Ocean Observing System and oceanographic expeditions from NOAA and CSIRO.

Behavior and Ecology

Social structure at rookeries has been documented in long-term studies by Biosphere Reserve programs, field teams from British Antarctic Survey, Australian Antarctic Division, University of California, Santa Cruz, University of Cape Town, and behavioral ecologists publishing in Behavioral Ecology, Animal Behaviour, and Journal of Experimental Biology. Male agonistic behavior, vocalizations, and harem defense relate to mating system theories popularized by evolutionary biologists at University of Oxford and University of Cambridge. Diving physiology and adaptations, including oxygen storage and bradycardia, are subjects of research by Woods Hole Oceanographic Institution, Scripps Institution of Oceanography, Monterey Bay Aquarium Research Institute, University of Hawaii, and University of Washington using methodologies refined at Max Planck Institute for Ornithology.

Reproduction and Life Cycle

Breeding phenology, natal philopatry, and age at first reproduction are documented in longitudinal studies coordinated by British Antarctic Survey, Australian Antarctic Division, University of Tasmania, University of Auckland, and University of Buenos Aires. Females give birth on rookeries monitored by conservation agencies such as Directorate of National Parks (Argentina), Parks Australia, Department of Environment and Water (South Australia), South African National Parks, and researchers publishing in Marine Mammal Science. Pup growth rates, weaning intervals, and molting schedules are discussed in datasets archived at Global Biodiversity Information Facility, Dryad (repository), and institutional repositories at University of Cambridge and Harvard University.

Diet and Foraging

Foraging ecology emphasizes deep dives to mesopelagic and bathypelagic zones to prey on squid and fish species documented in surveys by NOAA Fisheries, Institute of Marine Research (Norway), Institut polaire français Paul-Émile Victor, CSIC (Spain), and ichthyologists at Natural History Museum, London and Museum National d'Histoire Naturelle (France). Prey taxa identified in stomach-content and stable-isotope studies include species cataloged by FishBase, research programs from Australian Antarctic Division, British Antarctic Survey, Monterey Bay Aquarium Research Institute, and analyses published in Deep-Sea Research and Marine Biology.

Conservation and Threats

Population trends, conservation status assessments, and threat analyses have been produced by IUCN, Convention on Migratory Species, Agreement on the Conservation of Marine Mammals, and national agencies including Parks Australia, South African National Parks, Servicio Nacional de Pesca y Acuicultura (Chile), and Dirección de Fauna y Flora (Argentina). Threats include historical exploitation by sealing industries documented in archives at National Archives (UK), National Library of Australia, Biblioteca Nacional de Chile, and impacts of climate change, fisheries bycatch studied by Food and Agriculture Organization, International Whaling Commission, and ocean warming effects modeled by Intergovernmental Panel on Climate Change and World Meteorological Organization. Conservation measures encompass protected areas established under frameworks from UN Environment Programme, Antarctic Treaty System, Convention on Biological Diversity, and regional management by Government of South Georgia and the South Sandwich Islands and Parks Victoria.

Category:Pinnipeds Category:Mirounga Category:Marine mammals of the Southern Ocean