Segregation of diets by sex and individual in South American fur seals

Detalhes bibliográficos
Autor(a) principal: de Lima, Renan C.
Data de Publicação: 2022
Outros Autores: Franco-Trecu, Valentina, Carrasco, Thayara S. [UNESP], Inchausti, Pablo, Secchi, Eduardo R., Botta, Silvina
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://dx.doi.org/10.1007/s10452-021-09915-9
http://hdl.handle.net/11449/222639
Resumo: Trophic niche width and individual specialization among marine predators are often subjected to seasonal constraints. Differences are expected to arise for sexually dimorphic species exposed to distinct ecological opportunities, as well as intrinsic differences in physiological abilities or energetic requirements. We assess seasonal and sexual differences in isotopic niche overlap and width and analyze inter-individual foraging variation throughout the year of the South American fur seal (Arctocephalus australis). We obtained chronologically ordered δ13C and δ15N data from vibrissae of 25 males and 24 females from southern Brazil and Uruguay. There were significant differences between sexes for both isotopes with males showing higher values (δ13C = − 14.5 ± 0.5‰; δ15N = 18.9 ± 1.2‰) than females (δ13C = − 15.2 ± 0.5‰; δ15N = 17.8 ± 1.2‰), but not among seasons or years. A very small isotopic niche overlap found between sexes (1.1–9.5%), with limited seasonal variation, likely resulted from differences in prey consumption and foraging habitats. Compared to other seasons, females had a wider isotopic niche in spring. While males showed seasonal stability in the foraging niche, females showed some small variation, which is probably influenced by central place foraging. Both sexes had considerable interindividual variation in estimated dietary composition and had different proportions of potential prey contribution at the population level. These findings enlighten the knowledge of South American fur seal trophic ecology, and how they may seasonally and spatially shift their foraging strategies according to their distinct life histories. It ultimately reflects in a small niche partitioning and possibly low intraspecific competition at the species northernmost area of occurrence in the western South Atlantic.
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spelling Segregation of diets by sex and individual in South American fur sealsArctocephalus australisAtlantic OceanForaging habitsIndividual specializationIsotopic nicheTrophic niche width and individual specialization among marine predators are often subjected to seasonal constraints. Differences are expected to arise for sexually dimorphic species exposed to distinct ecological opportunities, as well as intrinsic differences in physiological abilities or energetic requirements. We assess seasonal and sexual differences in isotopic niche overlap and width and analyze inter-individual foraging variation throughout the year of the South American fur seal (Arctocephalus australis). We obtained chronologically ordered δ13C and δ15N data from vibrissae of 25 males and 24 females from southern Brazil and Uruguay. There were significant differences between sexes for both isotopes with males showing higher values (δ13C = − 14.5 ± 0.5‰; δ15N = 18.9 ± 1.2‰) than females (δ13C = − 15.2 ± 0.5‰; δ15N = 17.8 ± 1.2‰), but not among seasons or years. A very small isotopic niche overlap found between sexes (1.1–9.5%), with limited seasonal variation, likely resulted from differences in prey consumption and foraging habitats. Compared to other seasons, females had a wider isotopic niche in spring. While males showed seasonal stability in the foraging niche, females showed some small variation, which is probably influenced by central place foraging. Both sexes had considerable interindividual variation in estimated dietary composition and had different proportions of potential prey contribution at the population level. These findings enlighten the knowledge of South American fur seal trophic ecology, and how they may seasonally and spatially shift their foraging strategies according to their distinct life histories. It ultimately reflects in a small niche partitioning and possibly low intraspecific competition at the species northernmost area of occurrence in the western South Atlantic.Agencia Nacional de Investigación e InnovaciónPrograma de Pós-Graduação em Oceanografia Biológica Instituto de Oceanografia Universidade Federal do Rio Grande (FURG)Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA) Instituto de Oceanografia Universidade Federal do Rio Grande (FURG)Departamento de Ecología y Evolución Facultad de Ciencias Universidad de la RepúblicaPrograma de Pós-Graduação em Biodiversidade de Ambientes Costeiros Instituto de Biociências Universidade Estadual Paulista (UNESP)Laboratório de Estratigrafia e Paleontologia Instituto de Biociências Universidade Estadual Paulista (UNESP)Centro Universitario Regional del Este Universidad de la RepúblicaPrograma de Pós-Graduação em Biodiversidade de Ambientes Costeiros Instituto de Biociências Universidade Estadual Paulista (UNESP)Laboratório de Estratigrafia e Paleontologia Instituto de Biociências Universidade Estadual Paulista (UNESP)Universidade Federal do Rio Grande (FURG)Universidad de la RepúblicaUniversidade Estadual Paulista (UNESP)de Lima, Renan C.Franco-Trecu, ValentinaCarrasco, Thayara S. [UNESP]Inchausti, PabloSecchi, Eduardo R.Botta, Silvina2022-04-28T19:45:55Z2022-04-28T19:45:55Z2022-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article251-267http://dx.doi.org/10.1007/s10452-021-09915-9Aquatic Ecology, v. 56, n. 1, p. 251-267, 2022.1573-51251386-2588http://hdl.handle.net/11449/22263910.1007/s10452-021-09915-92-s2.0-85117029217Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengAquatic Ecologyinfo:eu-repo/semantics/openAccess2022-04-28T19:45:55Zoai:repositorio.unesp.br:11449/222639Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T15:15:02.372258Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Segregation of diets by sex and individual in South American fur seals
title Segregation of diets by sex and individual in South American fur seals
spellingShingle Segregation of diets by sex and individual in South American fur seals
de Lima, Renan C.
Arctocephalus australis
Atlantic Ocean
Foraging habits
Individual specialization
Isotopic niche
title_short Segregation of diets by sex and individual in South American fur seals
title_full Segregation of diets by sex and individual in South American fur seals
title_fullStr Segregation of diets by sex and individual in South American fur seals
title_full_unstemmed Segregation of diets by sex and individual in South American fur seals
title_sort Segregation of diets by sex and individual in South American fur seals
author de Lima, Renan C.
author_facet de Lima, Renan C.
Franco-Trecu, Valentina
Carrasco, Thayara S. [UNESP]
Inchausti, Pablo
Secchi, Eduardo R.
Botta, Silvina
author_role author
author2 Franco-Trecu, Valentina
Carrasco, Thayara S. [UNESP]
Inchausti, Pablo
Secchi, Eduardo R.
Botta, Silvina
author2_role author
author
author
author
author
dc.contributor.none.fl_str_mv Universidade Federal do Rio Grande (FURG)
Universidad de la República
Universidade Estadual Paulista (UNESP)
dc.contributor.author.fl_str_mv de Lima, Renan C.
Franco-Trecu, Valentina
Carrasco, Thayara S. [UNESP]
Inchausti, Pablo
Secchi, Eduardo R.
Botta, Silvina
dc.subject.por.fl_str_mv Arctocephalus australis
Atlantic Ocean
Foraging habits
Individual specialization
Isotopic niche
topic Arctocephalus australis
Atlantic Ocean
Foraging habits
Individual specialization
Isotopic niche
description Trophic niche width and individual specialization among marine predators are often subjected to seasonal constraints. Differences are expected to arise for sexually dimorphic species exposed to distinct ecological opportunities, as well as intrinsic differences in physiological abilities or energetic requirements. We assess seasonal and sexual differences in isotopic niche overlap and width and analyze inter-individual foraging variation throughout the year of the South American fur seal (Arctocephalus australis). We obtained chronologically ordered δ13C and δ15N data from vibrissae of 25 males and 24 females from southern Brazil and Uruguay. There were significant differences between sexes for both isotopes with males showing higher values (δ13C = − 14.5 ± 0.5‰; δ15N = 18.9 ± 1.2‰) than females (δ13C = − 15.2 ± 0.5‰; δ15N = 17.8 ± 1.2‰), but not among seasons or years. A very small isotopic niche overlap found between sexes (1.1–9.5%), with limited seasonal variation, likely resulted from differences in prey consumption and foraging habitats. Compared to other seasons, females had a wider isotopic niche in spring. While males showed seasonal stability in the foraging niche, females showed some small variation, which is probably influenced by central place foraging. Both sexes had considerable interindividual variation in estimated dietary composition and had different proportions of potential prey contribution at the population level. These findings enlighten the knowledge of South American fur seal trophic ecology, and how they may seasonally and spatially shift their foraging strategies according to their distinct life histories. It ultimately reflects in a small niche partitioning and possibly low intraspecific competition at the species northernmost area of occurrence in the western South Atlantic.
publishDate 2022
dc.date.none.fl_str_mv 2022-04-28T19:45:55Z
2022-04-28T19:45:55Z
2022-03-01
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://dx.doi.org/10.1007/s10452-021-09915-9
Aquatic Ecology, v. 56, n. 1, p. 251-267, 2022.
1573-5125
1386-2588
http://hdl.handle.net/11449/222639
10.1007/s10452-021-09915-9
2-s2.0-85117029217
url http://dx.doi.org/10.1007/s10452-021-09915-9
http://hdl.handle.net/11449/222639
identifier_str_mv Aquatic Ecology, v. 56, n. 1, p. 251-267, 2022.
1573-5125
1386-2588
10.1007/s10452-021-09915-9
2-s2.0-85117029217
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Aquatic Ecology
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 251-267
dc.source.none.fl_str_mv Scopus
reponame:Repositório Institucional da UNESP
instname:Universidade Estadual Paulista (UNESP)
instacron:UNESP
instname_str Universidade Estadual Paulista (UNESP)
instacron_str UNESP
institution UNESP
reponame_str Repositório Institucional da UNESP
collection Repositório Institucional da UNESP
repository.name.fl_str_mv Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)
repository.mail.fl_str_mv
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