Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina

We studied seasonal variation in bird assemblages in a Chaco subtropical semiarid forest, Santiago del Estero Province, Argentina. We carried out seven samplings during both breeding and non breeding periods, in order to assess the resident status and the trophic guild of each species. During the la...

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Autores principales: Codesido, Mariano, Bilenca, David Norberto
Publicado: 2004
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063606_v36_n4_p544_Codesido
http://hdl.handle.net/20.500.12110/paper_00063606_v36_n4_p544_Codesido
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spelling paper:paper_00063606_v36_n4_p544_Codesido2023-06-08T14:31:20Z Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina Codesido, Mariano Bilenca, David Norberto Argentina Bird assemblages Chaco Diversity Subtropical semiaridforest Trophic guilds avifauna forest ecosystem seasonal variation semiarid region species diversity Argentina Santiago del Estero South America Western Hemisphere World Aves Galliformes Sporophila We studied seasonal variation in bird assemblages in a Chaco subtropical semiarid forest, Santiago del Estero Province, Argentina. We carried out seven samplings during both breeding and non breeding periods, in order to assess the resident status and the trophic guild of each species. During the last four samplings we recorded bird populations using 30 fixed-radius points, in order to estimate bird density, species density, evenness, and species diversity. We found that: (1) the bird assemblage had 96 species (67 residents, 19 summer migrants, 1 winter migrant, 5 of doubtful residency and 4 species whose resident status was unknown); (2) higher values of species density, evenness and species diversity were found during breeding periods; and (3) higher community attributes were followed by higher densities of 4 trophic guilds: nectarivores, frugivores and short and long-flight insectivores during the breeding periods. Changes in guild densities were probably associated with the arrival of summer migrants and to seasonal fluctuations in food resources, which in turn promoted seasonal changes in species density and diversity. Different from observations in other avian assemblages of the Chaco, no temporal variations were observed in the terrestrial seedeaters guild. This could be due to the fact that our study site forests are located in a landscape matrix with agricultural fields and grasslands that may offer year-round seed supply. The Chaco subtropical semiarid forest seems to be an important breeding habitat for many migrant species from both Neotropical and Nearctic regions. Fil:Codesido, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Bilenca, D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063606_v36_n4_p544_Codesido http://hdl.handle.net/20.500.12110/paper_00063606_v36_n4_p544_Codesido
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Argentina
Bird assemblages
Chaco
Diversity
Subtropical semiaridforest
Trophic guilds
avifauna
forest ecosystem
seasonal variation
semiarid region
species diversity
Argentina
Santiago del Estero
South America
Western Hemisphere
World
Aves
Galliformes
Sporophila
spellingShingle Argentina
Bird assemblages
Chaco
Diversity
Subtropical semiaridforest
Trophic guilds
avifauna
forest ecosystem
seasonal variation
semiarid region
species diversity
Argentina
Santiago del Estero
South America
Western Hemisphere
World
Aves
Galliformes
Sporophila
Codesido, Mariano
Bilenca, David Norberto
Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina
topic_facet Argentina
Bird assemblages
Chaco
Diversity
Subtropical semiaridforest
Trophic guilds
avifauna
forest ecosystem
seasonal variation
semiarid region
species diversity
Argentina
Santiago del Estero
South America
Western Hemisphere
World
Aves
Galliformes
Sporophila
description We studied seasonal variation in bird assemblages in a Chaco subtropical semiarid forest, Santiago del Estero Province, Argentina. We carried out seven samplings during both breeding and non breeding periods, in order to assess the resident status and the trophic guild of each species. During the last four samplings we recorded bird populations using 30 fixed-radius points, in order to estimate bird density, species density, evenness, and species diversity. We found that: (1) the bird assemblage had 96 species (67 residents, 19 summer migrants, 1 winter migrant, 5 of doubtful residency and 4 species whose resident status was unknown); (2) higher values of species density, evenness and species diversity were found during breeding periods; and (3) higher community attributes were followed by higher densities of 4 trophic guilds: nectarivores, frugivores and short and long-flight insectivores during the breeding periods. Changes in guild densities were probably associated with the arrival of summer migrants and to seasonal fluctuations in food resources, which in turn promoted seasonal changes in species density and diversity. Different from observations in other avian assemblages of the Chaco, no temporal variations were observed in the terrestrial seedeaters guild. This could be due to the fact that our study site forests are located in a landscape matrix with agricultural fields and grasslands that may offer year-round seed supply. The Chaco subtropical semiarid forest seems to be an important breeding habitat for many migrant species from both Neotropical and Nearctic regions.
author Codesido, Mariano
Bilenca, David Norberto
author_facet Codesido, Mariano
Bilenca, David Norberto
author_sort Codesido, Mariano
title Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina
title_short Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina
title_full Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina
title_fullStr Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina
title_full_unstemmed Seasonal variation in bird assemblages in subtropical semiarid forest of Chaco, Argentina
title_sort seasonal variation in bird assemblages in subtropical semiarid forest of chaco, argentina
publishDate 2004
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00063606_v36_n4_p544_Codesido
http://hdl.handle.net/20.500.12110/paper_00063606_v36_n4_p544_Codesido
work_keys_str_mv AT codesidomariano seasonalvariationinbirdassemblagesinsubtropicalsemiaridforestofchacoargentina
AT bilencadavidnorberto seasonalvariationinbirdassemblagesinsubtropicalsemiaridforestofchacoargentina
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