Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina

The population status of southern sea lions (Otaria flavescens) in southern Argentina (provinces of Santa Cruz and Tierra del Fuego) was last assessed between 1946 and 1949, when there were 49 colonies with 84,714 individuals and a production of 12,658 pups recorded. To update the population size an...

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Autores principales: Schiavini, A.C.M., Crespo, E.A., Szapkievich, V.
Formato: JOUR
Materias:
Otaria flavescens
Population
Southern Argentina
movement
pinniped
population estimation
reproduction
Argentina
Santa Cruz [Argentina]
South America
Tierra del Fuego [(PRV) Argentina]
Animalia
Mammalia
Otaria byronia
Otariidae
Panthera leo
Pinnipedia
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_16165047_v69_n2_p108_Schiavini
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_16165047_v69_n2_p108_Schiavini
record_format dspace
spelling todo:paper_16165047_v69_n2_p108_Schiavini2023-10-03T16:28:19Z Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina Schiavini, A.C.M. Crespo, E.A. Szapkievich, V. Otaria flavescens Population Southern Argentina movement pinniped population estimation reproduction Argentina Santa Cruz [Argentina] South America Tierra del Fuego [(PRV) Argentina] Animalia Mammalia Otaria byronia Otaria flavescens Otaria flavescens Otariidae Panthera leo Pinnipedia The population status of southern sea lions (Otaria flavescens) in southern Argentina (provinces of Santa Cruz and Tierra del Fuego) was last assessed between 1946 and 1949, when there were 49 colonies with 84,714 individuals and a production of 12,658 pups recorded. To update the population size and pup production a new series of surveys was carried out during 1992 and 1997, either from land, airplane or boat, using direct counts in the field or pictures. The number of pups was corrected using data from land-based counts. Overall, we recorded 53 colonies, with a minimum number of 12,310 animals present on land, including 2925 pups. This estimate represents a decrease to only 14.5% of the population size reported in the late 1940's. Applying a correction factor for animals in the water, the estimated total population was 22,157 individuals. The sealing activities performed mainly at northern Patagonia and at Tierra del Fuego are likely to be responsible for the depletion. We also detected changes in the location of the colonies. However, seasonal movements of animals were difficult to assess due to the scarce data available. Only four breeding colonies may be considered permanent. Seasonal movements would take place between the islets close to Ushuaia city and Islas Becasses. Southern Argentina does not hold large breeding colonies like those found, for example, in northern Patagonia. Juveniles predominate in the social structure of colonies. This suggests a likely increase in the coming years. Fil:Schiavini, A.C.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Crespo, E.A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Szapkievich, V. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_16165047_v69_n2_p108_Schiavini
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Otaria flavescens
Population
Southern Argentina
movement
pinniped
population estimation
reproduction
Argentina
Santa Cruz [Argentina]
South America
Tierra del Fuego [(PRV) Argentina]
Animalia
Mammalia
Otaria byronia
Otaria flavescens
Otaria flavescens
Otariidae
Panthera leo
Pinnipedia
spellingShingle Otaria flavescens
Population
Southern Argentina
movement
pinniped
population estimation
reproduction
Argentina
Santa Cruz [Argentina]
South America
Tierra del Fuego [(PRV) Argentina]
Animalia
Mammalia
Otaria byronia
Otaria flavescens
Otaria flavescens
Otariidae
Panthera leo
Pinnipedia
Schiavini, A.C.M.
Crespo, E.A.
Szapkievich, V.
Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina
topic_facet Otaria flavescens
Population
Southern Argentina
movement
pinniped
population estimation
reproduction
Argentina
Santa Cruz [Argentina]
South America
Tierra del Fuego [(PRV) Argentina]
Animalia
Mammalia
Otaria byronia
Otaria flavescens
Otaria flavescens
Otariidae
Panthera leo
Pinnipedia
description The population status of southern sea lions (Otaria flavescens) in southern Argentina (provinces of Santa Cruz and Tierra del Fuego) was last assessed between 1946 and 1949, when there were 49 colonies with 84,714 individuals and a production of 12,658 pups recorded. To update the population size and pup production a new series of surveys was carried out during 1992 and 1997, either from land, airplane or boat, using direct counts in the field or pictures. The number of pups was corrected using data from land-based counts. Overall, we recorded 53 colonies, with a minimum number of 12,310 animals present on land, including 2925 pups. This estimate represents a decrease to only 14.5% of the population size reported in the late 1940's. Applying a correction factor for animals in the water, the estimated total population was 22,157 individuals. The sealing activities performed mainly at northern Patagonia and at Tierra del Fuego are likely to be responsible for the depletion. We also detected changes in the location of the colonies. However, seasonal movements of animals were difficult to assess due to the scarce data available. Only four breeding colonies may be considered permanent. Seasonal movements would take place between the islets close to Ushuaia city and Islas Becasses. Southern Argentina does not hold large breeding colonies like those found, for example, in northern Patagonia. Juveniles predominate in the social structure of colonies. This suggests a likely increase in the coming years.
format JOUR
author Schiavini, A.C.M.
Crespo, E.A.
Szapkievich, V.
author_facet Schiavini, A.C.M.
Crespo, E.A.
Szapkievich, V.
author_sort Schiavini, A.C.M.
title Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina
title_short Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina
title_full Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina
title_fullStr Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina
title_full_unstemmed Status of the population of South American sea lion (Otaria flavescens Shaw, 1800) in southern Argentina
title_sort status of the population of south american sea lion (otaria flavescens shaw, 1800) in southern argentina
url http://hdl.handle.net/20.500.12110/paper_16165047_v69_n2_p108_Schiavini
work_keys_str_mv AT schiaviniacm statusofthepopulationofsouthamericansealionotariaflavescensshaw1800insouthernargentina
AT crespoea statusofthepopulationofsouthamericansealionotariaflavescensshaw1800insouthernargentina
AT szapkievichv statusofthepopulationofsouthamericansealionotariaflavescensshaw1800insouthernargentina
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