Improvement in survivorship: The key for population recovery?

Autores
Grandi, Maria Florencia; Dans, Silvana Laura; Crespo, Enrique Alberto
Año de publicación
2016
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
In northern Patagonia, commercial harvesting of South American sea lions, Otaria flavescens, from 1920 to 1960, decimated its population abundance. Population recovery was not immediate after hunting ceased in 1962. The population was stable until 1989, and since then has grown at an annual rate of increase of 5.7%. Along with this growth there was an increase of the juvenile fraction and changes in the social composition of colonies, which could be related to changes in some population vital rates. The aim of this study was to analyze changes in the survivorship pattern of Otaria flavescens through time. The ultimate goal was to contribute to a better understanding of changes that could have operated on the ecosystem after the decline and recovery of one of the main marine top-predators in the southern South Atlantic Ocean. The comparisons of survivorship curves of males and females, obtained from the life tables of two periods with different population trends: 1981-1987 (stationary) and 2000-2008 (recovering), showed that there were differences in survivorship between sexes, where recent female age-specific survival was higher than that of males at any age. The comparison of survivorship between periods showed differences in both sexes. Both juveniles and adults, both male and female, from the recent period showed higher survival than those of the 1980’s decade. This improvement in survivorship could be one of the essential factors that drove population recovery in the last decades. Here we discuss the possible hypotheses of which factors could have changed in the ecosystem to favour juvenile and adult survivorship, such as an increase in the availability of food recourses, a decrease of exogenous mortality causes, or a combination of both factors.
Fil: Grandi, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
Fil: Dans, Silvana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia; Argentina
Fil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia; Argentina
Materia
LIFE TABLE
NORTHERN PATAGONIA
OTARIA FLAVESCENS
POPULATION RECOVERY
SOUTH AMERICAN SEA LION
SURVIVORSHIP
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/39174
Acceder
id CONICETDig_a34749b109c609a5f09b8f2532ce7611
oai_identifier_str oai:ri.conicet.gov.ar:11336/39174
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Improvement in survivorship: The key for population recovery?Grandi, Maria FlorenciaDans, Silvana LauraCrespo, Enrique AlbertoLIFE TABLENORTHERN PATAGONIAOTARIA FLAVESCENSPOPULATION RECOVERYSOUTH AMERICAN SEA LIONSURVIVORSHIPhttps://purl.org/becyt/ford/1.6https://purl.org/becyt/ford/1In northern Patagonia, commercial harvesting of South American sea lions, Otaria flavescens, from 1920 to 1960, decimated its population abundance. Population recovery was not immediate after hunting ceased in 1962. The population was stable until 1989, and since then has grown at an annual rate of increase of 5.7%. Along with this growth there was an increase of the juvenile fraction and changes in the social composition of colonies, which could be related to changes in some population vital rates. The aim of this study was to analyze changes in the survivorship pattern of Otaria flavescens through time. The ultimate goal was to contribute to a better understanding of changes that could have operated on the ecosystem after the decline and recovery of one of the main marine top-predators in the southern South Atlantic Ocean. The comparisons of survivorship curves of males and females, obtained from the life tables of two periods with different population trends: 1981-1987 (stationary) and 2000-2008 (recovering), showed that there were differences in survivorship between sexes, where recent female age-specific survival was higher than that of males at any age. The comparison of survivorship between periods showed differences in both sexes. Both juveniles and adults, both male and female, from the recent period showed higher survival than those of the 1980’s decade. This improvement in survivorship could be one of the essential factors that drove population recovery in the last decades. Here we discuss the possible hypotheses of which factors could have changed in the ecosystem to favour juvenile and adult survivorship, such as an increase in the availability of food recourses, a decrease of exogenous mortality causes, or a combination of both factors.Fil: Grandi, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Dans, Silvana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia; ArgentinaFil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia; ArgentinaAcademia Sinica2016info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/39174Grandi, Maria Florencia; Dans, Silvana Laura; Crespo, Enrique Alberto; Improvement in survivorship: The key for population recovery?; Academia Sinica; Zoological Studies; 55; 9; 2016; 1-171021-55061810-522XCONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.6620/ZS.2016.55-09info:eu-repo/semantics/altIdentifier/url/http://zoolstud.sinica.edu.tw/Journals/55/55-09.htmlinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:02:43Zoai:ri.conicet.gov.ar:11336/39174instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-22 11:02:43.3CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Improvement in survivorship: The key for population recovery?
title Improvement in survivorship: The key for population recovery?
spellingShingle Improvement in survivorship: The key for population recovery?
Grandi, Maria Florencia
LIFE TABLE
NORTHERN PATAGONIA
OTARIA FLAVESCENS
POPULATION RECOVERY
SOUTH AMERICAN SEA LION
SURVIVORSHIP
title_short Improvement in survivorship: The key for population recovery?
title_full Improvement in survivorship: The key for population recovery?
title_fullStr Improvement in survivorship: The key for population recovery?
title_full_unstemmed Improvement in survivorship: The key for population recovery?
title_sort Improvement in survivorship: The key for population recovery?
dc.creator.none.fl_str_mv Grandi, Maria Florencia
Dans, Silvana Laura
Crespo, Enrique Alberto
author Grandi, Maria Florencia
author_facet Grandi, Maria Florencia
Dans, Silvana Laura
Crespo, Enrique Alberto
author_role author
author2 Dans, Silvana Laura
Crespo, Enrique Alberto
author2_role author
author
dc.subject.none.fl_str_mv LIFE TABLE
NORTHERN PATAGONIA
OTARIA FLAVESCENS
POPULATION RECOVERY
SOUTH AMERICAN SEA LION
SURVIVORSHIP
topic LIFE TABLE
NORTHERN PATAGONIA
OTARIA FLAVESCENS
POPULATION RECOVERY
SOUTH AMERICAN SEA LION
SURVIVORSHIP
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv In northern Patagonia, commercial harvesting of South American sea lions, Otaria flavescens, from 1920 to 1960, decimated its population abundance. Population recovery was not immediate after hunting ceased in 1962. The population was stable until 1989, and since then has grown at an annual rate of increase of 5.7%. Along with this growth there was an increase of the juvenile fraction and changes in the social composition of colonies, which could be related to changes in some population vital rates. The aim of this study was to analyze changes in the survivorship pattern of Otaria flavescens through time. The ultimate goal was to contribute to a better understanding of changes that could have operated on the ecosystem after the decline and recovery of one of the main marine top-predators in the southern South Atlantic Ocean. The comparisons of survivorship curves of males and females, obtained from the life tables of two periods with different population trends: 1981-1987 (stationary) and 2000-2008 (recovering), showed that there were differences in survivorship between sexes, where recent female age-specific survival was higher than that of males at any age. The comparison of survivorship between periods showed differences in both sexes. Both juveniles and adults, both male and female, from the recent period showed higher survival than those of the 1980’s decade. This improvement in survivorship could be one of the essential factors that drove population recovery in the last decades. Here we discuss the possible hypotheses of which factors could have changed in the ecosystem to favour juvenile and adult survivorship, such as an increase in the availability of food recourses, a decrease of exogenous mortality causes, or a combination of both factors.
Fil: Grandi, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
Fil: Dans, Silvana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia; Argentina
Fil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Universidad Nacional de la Patagonia; Argentina
description In northern Patagonia, commercial harvesting of South American sea lions, Otaria flavescens, from 1920 to 1960, decimated its population abundance. Population recovery was not immediate after hunting ceased in 1962. The population was stable until 1989, and since then has grown at an annual rate of increase of 5.7%. Along with this growth there was an increase of the juvenile fraction and changes in the social composition of colonies, which could be related to changes in some population vital rates. The aim of this study was to analyze changes in the survivorship pattern of Otaria flavescens through time. The ultimate goal was to contribute to a better understanding of changes that could have operated on the ecosystem after the decline and recovery of one of the main marine top-predators in the southern South Atlantic Ocean. The comparisons of survivorship curves of males and females, obtained from the life tables of two periods with different population trends: 1981-1987 (stationary) and 2000-2008 (recovering), showed that there were differences in survivorship between sexes, where recent female age-specific survival was higher than that of males at any age. The comparison of survivorship between periods showed differences in both sexes. Both juveniles and adults, both male and female, from the recent period showed higher survival than those of the 1980’s decade. This improvement in survivorship could be one of the essential factors that drove population recovery in the last decades. Here we discuss the possible hypotheses of which factors could have changed in the ecosystem to favour juvenile and adult survivorship, such as an increase in the availability of food recourses, a decrease of exogenous mortality causes, or a combination of both factors.
publishDate 2016
dc.date.none.fl_str_mv 2016
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/39174
Grandi, Maria Florencia; Dans, Silvana Laura; Crespo, Enrique Alberto; Improvement in survivorship: The key for population recovery?; Academia Sinica; Zoological Studies; 55; 9; 2016; 1-17
1021-5506
1810-522X
CONICET Digital
CONICET
url http://hdl.handle.net/11336/39174
identifier_str_mv Grandi, Maria Florencia; Dans, Silvana Laura; Crespo, Enrique Alberto; Improvement in survivorship: The key for population recovery?; Academia Sinica; Zoological Studies; 55; 9; 2016; 1-17
1021-5506
1810-522X
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.6620/ZS.2016.55-09
info:eu-repo/semantics/altIdentifier/url/http://zoolstud.sinica.edu.tw/Journals/55/55-09.html
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Academia Sinica
publisher.none.fl_str_mv Academia Sinica
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
_version_ 1846781242571227136
score 12.982451

Publicaciones similares