Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported

Autores
Travaini, Alejandro; Zapata, Sonia Cristina; Bustamante, Javier; Pedrana, Julieta; Zanón Martínez, Juan Ignacio; Rodriguez, Alejandro
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Background: Guanacos (Lama guanicoe) are thought to have declined in Patagonia mainly as a result of hunting and sheep ranching. Currently accepted estimates of total population size are extrapolated from densities obtained through strip transects in local studies. We used road surveys (8,141 km) and distance sampling to estimate guanaco density and population size over major environmental gradients of Santa Cruz, a large region in southern Patagonia. We also calculated the survey effort required to detect population trends in Santa Cruz. Results: We found considerable spatial variation in density (1.1 to 7.4 ind/km2), with a mean value of 4.8 ind/km2, which is more than twice the mean value guessed for central and northern Patagonia. Consequently, guanaco numbers in Santa Cruz were estimated at 1.1 million individuals (95% CI 0.7 to 1.6), which almost doubles current estimates of guanaco population size in South America. High guanaco abundance was found in arid lands, overgrazed and unable to support profitable sheep stocks. Detecting a 50% change in guanaco population size over a 10-year period requires substantial monitoring effort: the annual survey of between 40 and 80 30-km transects, which becomes up to 120 transects if trends are to be detected over 5 years. Conclusions: Regional patterns in guanaco density can only be detected through large-scale surveys. Coupling these surveys with distance sampling techniques produce robust estimates of density and its variation. Figures so obtained improve currently available estimates of guanaco population size across its geographic range, which seem to be extrapolated from strip counts over small areas. In arid lands degraded by sheep overgrazing, sustainable use of guanaco populations would help harmonize guanaco conservation, socio-economic progress of rural areas, and eventually the restoration of shrub-steppes.
EEA Balcarce
Fil: Travaini, Alejandro. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Zapata, Sonia Cristina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina
Fil: Bustamante, Javier. Consejo Superior de Investigaciones Científicas (CSIC). Estación Biológica de Doñana. Department of Wetland EcologyRemote Sensing and GIS Lab; España
Fil: Pedrana, Julieta. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina
Fil: Zanón Martínez, Juan Ignacio. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Centro para el Estudio y Conservación de las Aves Rapaces en Argentina; Argentina
Fil: Rodriguez, Alejandro. Consejo Superior de Investigaciones Científicas (CSIC). Estación Biológica de Doñana. Department of Conservation Biology; España
Fuente
Zoological Studies 54 : 23 (December 2015)
Materia
Guanaco
Población Animal
Vigilancia
Sostenibilidad
Muestreo
Guanacos
Animal Population
Monitoring
Sustainability
Sampling
Región Patagónica
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
INTA Digital (INTA)
Institución
Instituto Nacional de Tecnología Agropecuaria
OAI Identificador
oai:localhost:20.500.12123/4558
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oai_identifier_str oai:localhost:20.500.12123/4558
network_acronym_str INTADig
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network_name_str INTA Digital (INTA)
spelling Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reportedTravaini, AlejandroZapata, Sonia CristinaBustamante, JavierPedrana, JulietaZanón Martínez, Juan IgnacioRodriguez, AlejandroGuanacoPoblación AnimalVigilanciaSostenibilidadMuestreoGuanacosAnimal PopulationMonitoringSustainabilitySamplingRegión PatagónicaBackground: Guanacos (Lama guanicoe) are thought to have declined in Patagonia mainly as a result of hunting and sheep ranching. Currently accepted estimates of total population size are extrapolated from densities obtained through strip transects in local studies. We used road surveys (8,141 km) and distance sampling to estimate guanaco density and population size over major environmental gradients of Santa Cruz, a large region in southern Patagonia. We also calculated the survey effort required to detect population trends in Santa Cruz. Results: We found considerable spatial variation in density (1.1 to 7.4 ind/km2), with a mean value of 4.8 ind/km2, which is more than twice the mean value guessed for central and northern Patagonia. Consequently, guanaco numbers in Santa Cruz were estimated at 1.1 million individuals (95% CI 0.7 to 1.6), which almost doubles current estimates of guanaco population size in South America. High guanaco abundance was found in arid lands, overgrazed and unable to support profitable sheep stocks. Detecting a 50% change in guanaco population size over a 10-year period requires substantial monitoring effort: the annual survey of between 40 and 80 30-km transects, which becomes up to 120 transects if trends are to be detected over 5 years. Conclusions: Regional patterns in guanaco density can only be detected through large-scale surveys. Coupling these surveys with distance sampling techniques produce robust estimates of density and its variation. Figures so obtained improve currently available estimates of guanaco population size across its geographic range, which seem to be extrapolated from strip counts over small areas. In arid lands degraded by sheep overgrazing, sustainable use of guanaco populations would help harmonize guanaco conservation, socio-economic progress of rural areas, and eventually the restoration of shrub-steppes.EEA BalcarceFil: Travaini, Alejandro. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zapata, Sonia Cristina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; ArgentinaFil: Bustamante, Javier. Consejo Superior de Investigaciones Científicas (CSIC). Estación Biológica de Doñana. Department of Wetland EcologyRemote Sensing and GIS Lab; EspañaFil: Pedrana, Julieta. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Zanón Martínez, Juan Ignacio. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Centro para el Estudio y Conservación de las Aves Rapaces en Argentina; ArgentinaFil: Rodriguez, Alejandro. Consejo Superior de Investigaciones Científicas (CSIC). Estación Biológica de Doñana. Department of Conservation Biology; EspañaSpringer2019-03-08T13:33:43Z2019-03-08T13:33:43Z2015-12info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfhttps://link.springer.com/article/10.1186/s40555-014-0097-0http://hdl.handle.net/20.500.12123/45581810-522Xhttps://doi.org/10.1186/s40555-014-0097-0Zoological Studies 54 : 23 (December 2015)reponame:INTA Digital (INTA)instname:Instituto Nacional de Tecnología Agropecuariaenginfo:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)2025-09-29T13:44:35Zoai:localhost:20.500.12123/4558instacron:INTAInstitucionalhttp://repositorio.inta.gob.ar/Organismo científico-tecnológicoNo correspondehttp://repositorio.inta.gob.ar/oai/requesttripaldi.nicolas@inta.gob.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:l2025-09-29 13:44:35.834INTA Digital (INTA) - Instituto Nacional de Tecnología Agropecuariafalse
dc.title.none.fl_str_mv Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
title Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
spellingShingle Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
Travaini, Alejandro
Guanaco
Población Animal
Vigilancia
Sostenibilidad
Muestreo
Guanacos
Animal Population
Monitoring
Sustainability
Sampling
Región Patagónica
title_short Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
title_full Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
title_fullStr Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
title_full_unstemmed Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
title_sort Guanaco abundance and monitoring in Southern Patagonia: distance sampling reveals substantially greater numbers than previously reported
dc.creator.none.fl_str_mv Travaini, Alejandro
Zapata, Sonia Cristina
Bustamante, Javier
Pedrana, Julieta
Zanón Martínez, Juan Ignacio
Rodriguez, Alejandro
author Travaini, Alejandro
author_facet Travaini, Alejandro
Zapata, Sonia Cristina
Bustamante, Javier
Pedrana, Julieta
Zanón Martínez, Juan Ignacio
Rodriguez, Alejandro
author_role author
author2 Zapata, Sonia Cristina
Bustamante, Javier
Pedrana, Julieta
Zanón Martínez, Juan Ignacio
Rodriguez, Alejandro
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Guanaco
Población Animal
Vigilancia
Sostenibilidad
Muestreo
Guanacos
Animal Population
Monitoring
Sustainability
Sampling
Región Patagónica
topic Guanaco
Población Animal
Vigilancia
Sostenibilidad
Muestreo
Guanacos
Animal Population
Monitoring
Sustainability
Sampling
Región Patagónica
dc.description.none.fl_txt_mv Background: Guanacos (Lama guanicoe) are thought to have declined in Patagonia mainly as a result of hunting and sheep ranching. Currently accepted estimates of total population size are extrapolated from densities obtained through strip transects in local studies. We used road surveys (8,141 km) and distance sampling to estimate guanaco density and population size over major environmental gradients of Santa Cruz, a large region in southern Patagonia. We also calculated the survey effort required to detect population trends in Santa Cruz. Results: We found considerable spatial variation in density (1.1 to 7.4 ind/km2), with a mean value of 4.8 ind/km2, which is more than twice the mean value guessed for central and northern Patagonia. Consequently, guanaco numbers in Santa Cruz were estimated at 1.1 million individuals (95% CI 0.7 to 1.6), which almost doubles current estimates of guanaco population size in South America. High guanaco abundance was found in arid lands, overgrazed and unable to support profitable sheep stocks. Detecting a 50% change in guanaco population size over a 10-year period requires substantial monitoring effort: the annual survey of between 40 and 80 30-km transects, which becomes up to 120 transects if trends are to be detected over 5 years. Conclusions: Regional patterns in guanaco density can only be detected through large-scale surveys. Coupling these surveys with distance sampling techniques produce robust estimates of density and its variation. Figures so obtained improve currently available estimates of guanaco population size across its geographic range, which seem to be extrapolated from strip counts over small areas. In arid lands degraded by sheep overgrazing, sustainable use of guanaco populations would help harmonize guanaco conservation, socio-economic progress of rural areas, and eventually the restoration of shrub-steppes.
EEA Balcarce
Fil: Travaini, Alejandro. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Zapata, Sonia Cristina. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina
Fil: Bustamante, Javier. Consejo Superior de Investigaciones Científicas (CSIC). Estación Biológica de Doñana. Department of Wetland EcologyRemote Sensing and GIS Lab; España
Fil: Pedrana, Julieta. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina
Fil: Zanón Martínez, Juan Ignacio. Universidad Nacional de la Patagonia Austral. Unidad Académica Caleta Olivia. Centro de Investigaciones Puerto Deseado; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Centro para el Estudio y Conservación de las Aves Rapaces en Argentina; Argentina
Fil: Rodriguez, Alejandro. Consejo Superior de Investigaciones Científicas (CSIC). Estación Biológica de Doñana. Department of Conservation Biology; España
description Background: Guanacos (Lama guanicoe) are thought to have declined in Patagonia mainly as a result of hunting and sheep ranching. Currently accepted estimates of total population size are extrapolated from densities obtained through strip transects in local studies. We used road surveys (8,141 km) and distance sampling to estimate guanaco density and population size over major environmental gradients of Santa Cruz, a large region in southern Patagonia. We also calculated the survey effort required to detect population trends in Santa Cruz. Results: We found considerable spatial variation in density (1.1 to 7.4 ind/km2), with a mean value of 4.8 ind/km2, which is more than twice the mean value guessed for central and northern Patagonia. Consequently, guanaco numbers in Santa Cruz were estimated at 1.1 million individuals (95% CI 0.7 to 1.6), which almost doubles current estimates of guanaco population size in South America. High guanaco abundance was found in arid lands, overgrazed and unable to support profitable sheep stocks. Detecting a 50% change in guanaco population size over a 10-year period requires substantial monitoring effort: the annual survey of between 40 and 80 30-km transects, which becomes up to 120 transects if trends are to be detected over 5 years. Conclusions: Regional patterns in guanaco density can only be detected through large-scale surveys. Coupling these surveys with distance sampling techniques produce robust estimates of density and its variation. Figures so obtained improve currently available estimates of guanaco population size across its geographic range, which seem to be extrapolated from strip counts over small areas. In arid lands degraded by sheep overgrazing, sustainable use of guanaco populations would help harmonize guanaco conservation, socio-economic progress of rural areas, and eventually the restoration of shrub-steppes.
publishDate 2015
dc.date.none.fl_str_mv 2015-12
2019-03-08T13:33:43Z
2019-03-08T13:33:43Z
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://link.springer.com/article/10.1186/s40555-014-0097-0
http://hdl.handle.net/20.500.12123/4558
1810-522X
https://doi.org/10.1186/s40555-014-0097-0
url https://link.springer.com/article/10.1186/s40555-014-0097-0
http://hdl.handle.net/20.500.12123/4558
https://doi.org/10.1186/s40555-014-0097-0
identifier_str_mv 1810-522X
dc.language.none.fl_str_mv eng
language eng
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
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eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Springer
publisher.none.fl_str_mv Springer
dc.source.none.fl_str_mv Zoological Studies 54 : 23 (December 2015)
reponame:INTA Digital (INTA)
instname:Instituto Nacional de Tecnología Agropecuaria
reponame_str INTA Digital (INTA)
collection INTA Digital (INTA)
instname_str Instituto Nacional de Tecnología Agropecuaria
repository.name.fl_str_mv INTA Digital (INTA) - Instituto Nacional de Tecnología Agropecuaria
repository.mail.fl_str_mv tripaldi.nicolas@inta.gob.ar
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