Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions

Autores
Marino, Andrea Ivana
Año de publicación
2010
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
According to current theory, anti-predator benefits promote group formation in open-dwelling ungulates. An inverse relationship between vigilance effort and group size has been documented frequently and thought to reflect the consequent decrease in perceived predation risk as group size increases. In contrast, competition costs are supposed to set the upper limit to the number of individuals that can forage together. As anti-predator behavior is no longer functional in the absence of predation and competition costs might be affected by resource distribution, the net benefit of aggregation will depend on the particular combination of predation risk and habitat structure experienced by the individual. To test this hypothesis, group-size effects on female time allocation and within-group aggression rate were compared between two guanaco populations exposed to contrasting levels of puma predation. Habitat structure within both sites consisted of mosaics of shrublands and grasslands, and group-size effects were also compared between these habitat types. Females under predation risk showed a strong reduction in vigilance as the number of adults in the group increased, whereas females from the predator-free population showed overall low levels of vigilance, regardless of group size. These results emphasize the anti-predator significance of the group-size effect on female vigilance, as well as guanaco plasticity to adjust time allocation to local conditions. On the other hand, within-group aggression rate increased with the number of adults in the group. Aggression rate was almost null within groups located in grasslands but was significantly higher in shrublands, regardless of predation risk, suggesting that the more heterogeneous distribution of shrubs increases the interference competition level. These results strengthen the notion of predation pressure and habitat structure as major determinants of the balance between costs and benefits of group living, and highlight the potential of individual behavioral patterns to make qualitative predictions about group-size variation within territorial ungulates.
Fil: Marino, Andrea Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
Materia
SOCIALITY
ANTIPREDATOR BENEFITS
COMPETITION COSTS
GUANACO
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/94218

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spelling Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological ConditionsMarino, Andrea IvanaSOCIALITYANTIPREDATOR BENEFITSCOMPETITION COSTSGUANACOhttps://purl.org/becyt/ford/1.6https://purl.org/becyt/ford/1According to current theory, anti-predator benefits promote group formation in open-dwelling ungulates. An inverse relationship between vigilance effort and group size has been documented frequently and thought to reflect the consequent decrease in perceived predation risk as group size increases. In contrast, competition costs are supposed to set the upper limit to the number of individuals that can forage together. As anti-predator behavior is no longer functional in the absence of predation and competition costs might be affected by resource distribution, the net benefit of aggregation will depend on the particular combination of predation risk and habitat structure experienced by the individual. To test this hypothesis, group-size effects on female time allocation and within-group aggression rate were compared between two guanaco populations exposed to contrasting levels of puma predation. Habitat structure within both sites consisted of mosaics of shrublands and grasslands, and group-size effects were also compared between these habitat types. Females under predation risk showed a strong reduction in vigilance as the number of adults in the group increased, whereas females from the predator-free population showed overall low levels of vigilance, regardless of group size. These results emphasize the anti-predator significance of the group-size effect on female vigilance, as well as guanaco plasticity to adjust time allocation to local conditions. On the other hand, within-group aggression rate increased with the number of adults in the group. Aggression rate was almost null within groups located in grasslands but was significantly higher in shrublands, regardless of predation risk, suggesting that the more heterogeneous distribution of shrubs increases the interference competition level. These results strengthen the notion of predation pressure and habitat structure as major determinants of the balance between costs and benefits of group living, and highlight the potential of individual behavioral patterns to make qualitative predictions about group-size variation within territorial ungulates.Fil: Marino, Andrea Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaWiley Blackwell Publishing, Inc2010-11info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/94218Marino, Andrea Ivana; Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions; Wiley Blackwell Publishing, Inc; Ethology; 116; 11; 11-2010; 999-10100179-1613CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/doi/10.1111/j.1439-0310.2010.01812.xinfo:eu-repo/semantics/altIdentifier/url/https://onlinelibrary.wiley.com/doi/full/10.1111/j.1439-0310.2010.01812.xinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-09-29T10:44:48Zoai:ri.conicet.gov.ar:11336/94218instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-09-29 10:44:49.17CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
title Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
spellingShingle Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
Marino, Andrea Ivana
SOCIALITY
ANTIPREDATOR BENEFITS
COMPETITION COSTS
GUANACO
title_short Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
title_full Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
title_fullStr Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
title_full_unstemmed Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
title_sort Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions
dc.creator.none.fl_str_mv Marino, Andrea Ivana
author Marino, Andrea Ivana
author_facet Marino, Andrea Ivana
author_role author
dc.subject.none.fl_str_mv SOCIALITY
ANTIPREDATOR BENEFITS
COMPETITION COSTS
GUANACO
topic SOCIALITY
ANTIPREDATOR BENEFITS
COMPETITION COSTS
GUANACO
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv According to current theory, anti-predator benefits promote group formation in open-dwelling ungulates. An inverse relationship between vigilance effort and group size has been documented frequently and thought to reflect the consequent decrease in perceived predation risk as group size increases. In contrast, competition costs are supposed to set the upper limit to the number of individuals that can forage together. As anti-predator behavior is no longer functional in the absence of predation and competition costs might be affected by resource distribution, the net benefit of aggregation will depend on the particular combination of predation risk and habitat structure experienced by the individual. To test this hypothesis, group-size effects on female time allocation and within-group aggression rate were compared between two guanaco populations exposed to contrasting levels of puma predation. Habitat structure within both sites consisted of mosaics of shrublands and grasslands, and group-size effects were also compared between these habitat types. Females under predation risk showed a strong reduction in vigilance as the number of adults in the group increased, whereas females from the predator-free population showed overall low levels of vigilance, regardless of group size. These results emphasize the anti-predator significance of the group-size effect on female vigilance, as well as guanaco plasticity to adjust time allocation to local conditions. On the other hand, within-group aggression rate increased with the number of adults in the group. Aggression rate was almost null within groups located in grasslands but was significantly higher in shrublands, regardless of predation risk, suggesting that the more heterogeneous distribution of shrubs increases the interference competition level. These results strengthen the notion of predation pressure and habitat structure as major determinants of the balance between costs and benefits of group living, and highlight the potential of individual behavioral patterns to make qualitative predictions about group-size variation within territorial ungulates.
Fil: Marino, Andrea Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
description According to current theory, anti-predator benefits promote group formation in open-dwelling ungulates. An inverse relationship between vigilance effort and group size has been documented frequently and thought to reflect the consequent decrease in perceived predation risk as group size increases. In contrast, competition costs are supposed to set the upper limit to the number of individuals that can forage together. As anti-predator behavior is no longer functional in the absence of predation and competition costs might be affected by resource distribution, the net benefit of aggregation will depend on the particular combination of predation risk and habitat structure experienced by the individual. To test this hypothesis, group-size effects on female time allocation and within-group aggression rate were compared between two guanaco populations exposed to contrasting levels of puma predation. Habitat structure within both sites consisted of mosaics of shrublands and grasslands, and group-size effects were also compared between these habitat types. Females under predation risk showed a strong reduction in vigilance as the number of adults in the group increased, whereas females from the predator-free population showed overall low levels of vigilance, regardless of group size. These results emphasize the anti-predator significance of the group-size effect on female vigilance, as well as guanaco plasticity to adjust time allocation to local conditions. On the other hand, within-group aggression rate increased with the number of adults in the group. Aggression rate was almost null within groups located in grasslands but was significantly higher in shrublands, regardless of predation risk, suggesting that the more heterogeneous distribution of shrubs increases the interference competition level. These results strengthen the notion of predation pressure and habitat structure as major determinants of the balance between costs and benefits of group living, and highlight the potential of individual behavioral patterns to make qualitative predictions about group-size variation within territorial ungulates.
publishDate 2010
dc.date.none.fl_str_mv 2010-11
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 http://hdl.handle.net/11336/94218
Marino, Andrea Ivana; Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions; Wiley Blackwell Publishing, Inc; Ethology; 116; 11; 11-2010; 999-1010
0179-1613
CONICET Digital
CONICET
url http://hdl.handle.net/11336/94218
identifier_str_mv Marino, Andrea Ivana; Costs and Benefits of Sociality Differ Between Female Guanacos Living in Contrasting Ecological Conditions; Wiley Blackwell Publishing, Inc; Ethology; 116; 11; 11-2010; 999-1010
0179-1613
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/doi/10.1111/j.1439-0310.2010.01812.x
info:eu-repo/semantics/altIdentifier/url/https://onlinelibrary.wiley.com/doi/full/10.1111/j.1439-0310.2010.01812.x
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
publisher.none.fl_str_mv Wiley Blackwell Publishing, Inc
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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