A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)

Detalhes bibliográficos
Autor(a) principal: Macpherson, Maggie P.
Data de Publicação: 2021
Outros Autores: Jahn, Alex E. [UNESP], Defreitas, Justin, Looknauth, Kooldeep, Wilson, Asaph, Baird, Leon, Defreitas, Kayla, Chiasson, Susan, Taylor, Caz
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://dx.doi.org/10.1676/20-00134
http://hdl.handle.net/11449/239901
Resumo: Understanding how diet and life history strategies interact is important for exploring constraints of available nutrition on energetically expensive life history events in wild animals (i.e., reproduction, annual migration, molt). Previous research on migratory birds breeding in the Northern Hemisphere has demonstrated trophic niche shifts from invertebrates to fruit in order to fuel spring migration. We examined whether a trophic niche shift occurred in a Neotropical austral migrant, the Fork-tailed Flycatcher (Tyrannus savana savana), prior to spring migration by measuring stable nitrogen isotopes in feathers. We found that the austral migrant subspecies T. s. savana did appear to shift in diet from a higher to a lower trophic level (consistent in pattern with a shift from a higher to a lower ratio of invertebrates to fruit) but the shift occurred earlier than expected if it was preparation for migration. A sympatric sedentary subspecies occupying the same habitat (T. s. monachus) appeared to forage only at the lower trophic level during its annual molt and showed no evidence of a trophic niche shift; however, the molt of the 2 subspecies occurs at slightly different times of year. The timing of the trophic niche shift leads us to conclude that a higher trophic level diet early in molt is not related to preparation for spring migration but that it may be related to seasonal changes in food availability as the wet season concludes. A remaining challenge for understanding the ecological consequences of trophic niche shifts is to find ways to empirically measure trade-offs between different diets across energetically expensive life history events and compare these between taxa with differing life history strategies.
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spelling A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)flycatchermigratory ecologystable nitrogen isotope analysisUnderstanding how diet and life history strategies interact is important for exploring constraints of available nutrition on energetically expensive life history events in wild animals (i.e., reproduction, annual migration, molt). Previous research on migratory birds breeding in the Northern Hemisphere has demonstrated trophic niche shifts from invertebrates to fruit in order to fuel spring migration. We examined whether a trophic niche shift occurred in a Neotropical austral migrant, the Fork-tailed Flycatcher (Tyrannus savana savana), prior to spring migration by measuring stable nitrogen isotopes in feathers. We found that the austral migrant subspecies T. s. savana did appear to shift in diet from a higher to a lower trophic level (consistent in pattern with a shift from a higher to a lower ratio of invertebrates to fruit) but the shift occurred earlier than expected if it was preparation for migration. A sympatric sedentary subspecies occupying the same habitat (T. s. monachus) appeared to forage only at the lower trophic level during its annual molt and showed no evidence of a trophic niche shift; however, the molt of the 2 subspecies occurs at slightly different times of year. The timing of the trophic niche shift leads us to conclude that a higher trophic level diet early in molt is not related to preparation for spring migration but that it may be related to seasonal changes in food availability as the wet season concludes. A remaining challenge for understanding the ecological consequences of trophic niche shifts is to find ways to empirically measure trade-offs between different diets across energetically expensive life history events and compare these between taxa with differing life history strategies.Tulane UniversityLouisiana State University Museum of Natural Science Louisiana State UniversityDepartment of Ecology and Evolutionary Biology Tulane UniversityEnvironmental Resilience Institute Indiana UniversityDepartamento de Zoologia Universidade Estadual PaulistaSouth Rupununi Conservation Society Wichabai Ranch, South RupununiBiology Department Loyola UniversityDepartamento de Zoologia Universidade Estadual PaulistaLouisiana State UniversityTulane UniversityIndiana UniversityUniversidade Estadual Paulista (UNESP)Wichabai RanchLoyola UniversityMacpherson, Maggie P.Jahn, Alex E. [UNESP]Defreitas, JustinLooknauth, KooldeepWilson, AsaphBaird, LeonDefreitas, KaylaChiasson, SusanTaylor, Caz2023-03-01T19:52:25Z2023-03-01T19:52:25Z2021-12-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article527-537http://dx.doi.org/10.1676/20-00134Wilson Journal of Ornithology, v. 133, n. 4, p. 527-537, 2021.1559-4491http://hdl.handle.net/11449/23990110.1676/20-001342-s2.0-85128371797Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengWilson Journal of Ornithologyinfo:eu-repo/semantics/openAccess2023-03-01T19:52:25Zoai:repositorio.unesp.br:11449/239901Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T19:13:27.443564Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
title A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
spellingShingle A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
Macpherson, Maggie P.
flycatcher
migratory ecology
stable nitrogen isotope analysis
title_short A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
title_full A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
title_fullStr A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
title_full_unstemmed A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
title_sort A trophic niche shift in a South American migrant: Stable nitrogen isotope signatures in feathers of Fork-tailed Flycatchers (Tyrannus savana)
author Macpherson, Maggie P.
author_facet Macpherson, Maggie P.
Jahn, Alex E. [UNESP]
Defreitas, Justin
Looknauth, Kooldeep
Wilson, Asaph
Baird, Leon
Defreitas, Kayla
Chiasson, Susan
Taylor, Caz
author_role author
author2 Jahn, Alex E. [UNESP]
Defreitas, Justin
Looknauth, Kooldeep
Wilson, Asaph
Baird, Leon
Defreitas, Kayla
Chiasson, Susan
Taylor, Caz
author2_role author
author
author
author
author
author
author
author
dc.contributor.none.fl_str_mv Louisiana State University
Tulane University
Indiana University
Universidade Estadual Paulista (UNESP)
Wichabai Ranch
Loyola University
dc.contributor.author.fl_str_mv Macpherson, Maggie P.
Jahn, Alex E. [UNESP]
Defreitas, Justin
Looknauth, Kooldeep
Wilson, Asaph
Baird, Leon
Defreitas, Kayla
Chiasson, Susan
Taylor, Caz
dc.subject.por.fl_str_mv flycatcher
migratory ecology
stable nitrogen isotope analysis
topic flycatcher
migratory ecology
stable nitrogen isotope analysis
description Understanding how diet and life history strategies interact is important for exploring constraints of available nutrition on energetically expensive life history events in wild animals (i.e., reproduction, annual migration, molt). Previous research on migratory birds breeding in the Northern Hemisphere has demonstrated trophic niche shifts from invertebrates to fruit in order to fuel spring migration. We examined whether a trophic niche shift occurred in a Neotropical austral migrant, the Fork-tailed Flycatcher (Tyrannus savana savana), prior to spring migration by measuring stable nitrogen isotopes in feathers. We found that the austral migrant subspecies T. s. savana did appear to shift in diet from a higher to a lower trophic level (consistent in pattern with a shift from a higher to a lower ratio of invertebrates to fruit) but the shift occurred earlier than expected if it was preparation for migration. A sympatric sedentary subspecies occupying the same habitat (T. s. monachus) appeared to forage only at the lower trophic level during its annual molt and showed no evidence of a trophic niche shift; however, the molt of the 2 subspecies occurs at slightly different times of year. The timing of the trophic niche shift leads us to conclude that a higher trophic level diet early in molt is not related to preparation for spring migration but that it may be related to seasonal changes in food availability as the wet season concludes. A remaining challenge for understanding the ecological consequences of trophic niche shifts is to find ways to empirically measure trade-offs between different diets across energetically expensive life history events and compare these between taxa with differing life history strategies.
publishDate 2021
dc.date.none.fl_str_mv 2021-12-01
2023-03-01T19:52:25Z
2023-03-01T19:52:25Z
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/10.1676/20-00134
Wilson Journal of Ornithology, v. 133, n. 4, p. 527-537, 2021.
1559-4491
http://hdl.handle.net/11449/239901
10.1676/20-00134
2-s2.0-85128371797
url http://dx.doi.org/10.1676/20-00134
http://hdl.handle.net/11449/239901
identifier_str_mv Wilson Journal of Ornithology, v. 133, n. 4, p. 527-537, 2021.
1559-4491
10.1676/20-00134
2-s2.0-85128371797
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Wilson Journal of Ornithology
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 527-537
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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