Segregation of diets by sex and individual in South American fur seals
Autor(a) principal: | |
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Data de Publicação: | 2022 |
Outros Autores: | , , , , |
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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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 |
|
_version_ |
1808128486698647552 |