Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones

Autores
Fraga, Rosendo Manuel
Año de publicación
1983
Idioma
español castellano
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Data on the brood parasitism of the Shiny Cowbird, Molothrus bonariensis on the Rufous-collared Sparrow, Zonotrlchia capensis, was collected during 10 breeding seasons (l970-1979: 70 nests), in a study site at Buenos Aires Province, Argentina. Though the cowbird parasitised 14 species of local passerines (40 %"of the total) most parasitic fledglings (46%), were reared by the sparrows. During the breeding season sparrows considerably outnumbered the cowbirds. Home ranges of banded female cowbirds ranged in size from 21 to 48 ha, and other females were not excluded; the females were rather gregarius.After 1975 the incidence of parasitism in nests of sparrows declined significantly; the overall incidence was 61,90%. Two morphs of cowbirds eggs were found in similar proportions in sparrow nests; measurements, size and shape of the egg morphs are included. The distribution of all cowbirds eggs in the nests of this accepter host departed significantly from Poisson and Preston (1948) distributions, but those of separate egg morphs agreed closely with expected distribution. Cowbird females laid 1 or 2 eggs per sparrow nest; with 1 exception, sets of 3 or more cowbird eggs represent parasitism by 2 or more females. The nesting success of host and parasite was low, being only 5,56% for cowbird eggs. Cowbirds destroyed relatively few (6,58%) cowbird eggs. In order to have 1 fledgling cowbird reared by sparrows each breeding season female cowbirds should lay 18 eggs in the nests of this host. The results are compared with those of other studies.
Fuente
Hornero (en línea) 1983;01extra(012):245-255
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc/2.5/ar
Repositorio
Biblioteca Digital (UBA-FCEN)
Institución
Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
OAI Identificador
hornero:hornero_v012_n01extra_p245

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network_name_str Biblioteca Digital (UBA-FCEN)
spelling Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusionesFraga, Rosendo ManuelData on the brood parasitism of the Shiny Cowbird, Molothrus bonariensis on the Rufous-collared Sparrow, Zonotrlchia capensis, was collected during 10 breeding seasons (l970-1979: 70 nests), in a study site at Buenos Aires Province, Argentina. Though the cowbird parasitised 14 species of local passerines (40 %"of the total) most parasitic fledglings (46%), were reared by the sparrows. During the breeding season sparrows considerably outnumbered the cowbirds. Home ranges of banded female cowbirds ranged in size from 21 to 48 ha, and other females were not excluded; the females were rather gregarius.After 1975 the incidence of parasitism in nests of sparrows declined significantly; the overall incidence was 61,90%. Two morphs of cowbirds eggs were found in similar proportions in sparrow nests; measurements, size and shape of the egg morphs are included. The distribution of all cowbirds eggs in the nests of this accepter host departed significantly from Poisson and Preston (1948) distributions, but those of separate egg morphs agreed closely with expected distribution. Cowbird females laid 1 or 2 eggs per sparrow nest; with 1 exception, sets of 3 or more cowbird eggs represent parasitism by 2 or more females. The nesting success of host and parasite was low, being only 5,56% for cowbird eggs. Cowbirds destroyed relatively few (6,58%) cowbird eggs. In order to have 1 fledgling cowbird reared by sparrows each breeding season female cowbirds should lay 18 eggs in the nests of this host. The results are compared with those of other studies.Aves Argentinas. Asociación Ornitológica del Plata1983-06info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttps://hdl.handle.net/20.500.12110/hornero_v012_n01extra_p245Hornero (en línea) 1983;01extra(012):245-255reponame:Biblioteca Digital (UBA-FCEN)instname:Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturalesinstacron:UBA-FCENspainfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc/2.5/ar2025-09-29T13:43:28Zhornero:hornero_v012_n01extra_p245Institucionalhttps://digital.bl.fcen.uba.ar/Universidad públicaNo correspondehttps://digital.bl.fcen.uba.ar/cgi-bin/oaiserver.cgiana@bl.fcen.uba.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:18962025-09-29 13:43:29.745Biblioteca Digital (UBA-FCEN) - Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturalesfalse
dc.title.none.fl_str_mv Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
title Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
spellingShingle Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
Fraga, Rosendo Manuel
title_short Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
title_full Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
title_fullStr Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
title_full_unstemmed Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
title_sort Parasitismo de cría del Renegrido, Molothrus bonariensis, sobre el Chingolo, Zonotrichia capensis : nuevas observaciones y conclusiones
dc.creator.none.fl_str_mv Fraga, Rosendo Manuel
author Fraga, Rosendo Manuel
author_facet Fraga, Rosendo Manuel
author_role author
dc.description.none.fl_txt_mv Data on the brood parasitism of the Shiny Cowbird, Molothrus bonariensis on the Rufous-collared Sparrow, Zonotrlchia capensis, was collected during 10 breeding seasons (l970-1979: 70 nests), in a study site at Buenos Aires Province, Argentina. Though the cowbird parasitised 14 species of local passerines (40 %"of the total) most parasitic fledglings (46%), were reared by the sparrows. During the breeding season sparrows considerably outnumbered the cowbirds. Home ranges of banded female cowbirds ranged in size from 21 to 48 ha, and other females were not excluded; the females were rather gregarius.After 1975 the incidence of parasitism in nests of sparrows declined significantly; the overall incidence was 61,90%. Two morphs of cowbirds eggs were found in similar proportions in sparrow nests; measurements, size and shape of the egg morphs are included. The distribution of all cowbirds eggs in the nests of this accepter host departed significantly from Poisson and Preston (1948) distributions, but those of separate egg morphs agreed closely with expected distribution. Cowbird females laid 1 or 2 eggs per sparrow nest; with 1 exception, sets of 3 or more cowbird eggs represent parasitism by 2 or more females. The nesting success of host and parasite was low, being only 5,56% for cowbird eggs. Cowbirds destroyed relatively few (6,58%) cowbird eggs. In order to have 1 fledgling cowbird reared by sparrows each breeding season female cowbirds should lay 18 eggs in the nests of this host. The results are compared with those of other studies.
description Data on the brood parasitism of the Shiny Cowbird, Molothrus bonariensis on the Rufous-collared Sparrow, Zonotrlchia capensis, was collected during 10 breeding seasons (l970-1979: 70 nests), in a study site at Buenos Aires Province, Argentina. Though the cowbird parasitised 14 species of local passerines (40 %"of the total) most parasitic fledglings (46%), were reared by the sparrows. During the breeding season sparrows considerably outnumbered the cowbirds. Home ranges of banded female cowbirds ranged in size from 21 to 48 ha, and other females were not excluded; the females were rather gregarius.After 1975 the incidence of parasitism in nests of sparrows declined significantly; the overall incidence was 61,90%. Two morphs of cowbirds eggs were found in similar proportions in sparrow nests; measurements, size and shape of the egg morphs are included. The distribution of all cowbirds eggs in the nests of this accepter host departed significantly from Poisson and Preston (1948) distributions, but those of separate egg morphs agreed closely with expected distribution. Cowbird females laid 1 or 2 eggs per sparrow nest; with 1 exception, sets of 3 or more cowbird eggs represent parasitism by 2 or more females. The nesting success of host and parasite was low, being only 5,56% for cowbird eggs. Cowbirds destroyed relatively few (6,58%) cowbird eggs. In order to have 1 fledgling cowbird reared by sparrows each breeding season female cowbirds should lay 18 eggs in the nests of this host. The results are compared with those of other studies.
publishDate 1983
dc.date.none.fl_str_mv 1983-06
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 https://hdl.handle.net/20.500.12110/hornero_v012_n01extra_p245
url https://hdl.handle.net/20.500.12110/hornero_v012_n01extra_p245
dc.language.none.fl_str_mv spa
language spa
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc/2.5/ar
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc/2.5/ar
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Aves Argentinas. Asociación Ornitológica del Plata
publisher.none.fl_str_mv Aves Argentinas. Asociación Ornitológica del Plata
dc.source.none.fl_str_mv Hornero (en línea) 1983;01extra(012):245-255
reponame:Biblioteca Digital (UBA-FCEN)
instname:Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
instacron:UBA-FCEN
reponame_str Biblioteca Digital (UBA-FCEN)
collection Biblioteca Digital (UBA-FCEN)
instname_str Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
instacron_str UBA-FCEN
institution UBA-FCEN
repository.name.fl_str_mv Biblioteca Digital (UBA-FCEN) - Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales
repository.mail.fl_str_mv ana@bl.fcen.uba.ar
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score 13.070432