Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil

Detalhes bibliográficos
Autor(a) principal: Freitas, Ana Cristina
Data de Publicação: 2004
Outros Autores: Kinas, Paul Gerhard, Martins, Cristiane Cavalcante Albuquerque, Coitinho, Márcia Helena Engel
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da FURG (RI FURG)
Texto Completo: http://repositorio.furg.br/handle/1/932
Resumo: Abundance estimates are presented for the humpback whales wintering off Brazil which ‘visit’ a surveyed area off Abrolhos Bank and display fluke-exposing behaviour. The study is based on photo-identification data collected between 1996 and 2000. Chapman-corrected Petersen estimates for all pairs of data result in estimates from 1,948 individuals up to 3,001 with coefficients of variation around 0.25. A more elaborate closed population multiple-recapture maximum-likelihood estimate is 2,393 with 95% profile-likelihood confidence interval (CI=1,924, 3,060). Replacing the closed-population assumption with a population allowed to grow (or decrease) according to some constant rate over the study period, the maximum-likelihood estimate of population size for the year 2000 becomes 3,871 (CI=2,795, 5,542) associated to an estimated annual growth rate of 31% over the study period and in the surveyed area. Although the inclusion of the growth rate results in a less restrictive assumption about population size, it is unclear at this time how to interpret it since the population around the Abrolhos Bank is some (unknown) fraction of whales wintering off Brazil. Alternatively, a fit of Whitehead’s model allowing for emigration and re-immigration gives an estimate of about 3,000 whales (CI=2,500, 3,650).
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spelling Abundance of humpback whales on the Abrolhos Bank wintering ground, BrazilAbundance estimateAtlantic OceanBreeding groundHumpback whalePhoto-idSouth AmericaAbundance estimates are presented for the humpback whales wintering off Brazil which ‘visit’ a surveyed area off Abrolhos Bank and display fluke-exposing behaviour. The study is based on photo-identification data collected between 1996 and 2000. Chapman-corrected Petersen estimates for all pairs of data result in estimates from 1,948 individuals up to 3,001 with coefficients of variation around 0.25. A more elaborate closed population multiple-recapture maximum-likelihood estimate is 2,393 with 95% profile-likelihood confidence interval (CI=1,924, 3,060). Replacing the closed-population assumption with a population allowed to grow (or decrease) according to some constant rate over the study period, the maximum-likelihood estimate of population size for the year 2000 becomes 3,871 (CI=2,795, 5,542) associated to an estimated annual growth rate of 31% over the study period and in the surveyed area. Although the inclusion of the growth rate results in a less restrictive assumption about population size, it is unclear at this time how to interpret it since the population around the Abrolhos Bank is some (unknown) fraction of whales wintering off Brazil. Alternatively, a fit of Whitehead’s model allowing for emigration and re-immigration gives an estimate of about 3,000 whales (CI=2,500, 3,650).2011-08-25T01:47:25Z2011-08-25T01:47:25Z2004info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfFREITAS, Ana et al. Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil. The Journal of Cetacean Research and Management, v. 6, n. 3, p. 225-230, 2004. Disponível em: <http://mardecetaceos.net/media_files/download/Freitasetal2004AbundancdeHumpbackinBrazil.pdf>. Acesso em: 24 ago. 2011.http://repositorio.furg.br/handle/1/932engFreitas, Ana CristinaKinas, Paul GerhardMartins, Cristiane Cavalcante AlbuquerqueCoitinho, Márcia Helena Engelinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da FURG (RI FURG)instname:Universidade Federal do Rio Grande (FURG)instacron:FURG2014-09-09T14:55:41Zoai:repositorio.furg.br:1/932Repositório InstitucionalPUBhttps://repositorio.furg.br/oai/request || http://200.19.254.174/oai/requestopendoar:2014-09-09T14:55:41Repositório Institucional da FURG (RI FURG) - Universidade Federal do Rio Grande (FURG)false
dc.title.none.fl_str_mv Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
title Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
spellingShingle Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
Freitas, Ana Cristina
Abundance estimate
Atlantic Ocean
Breeding ground
Humpback whale
Photo-id
South America
title_short Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
title_full Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
title_fullStr Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
title_full_unstemmed Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
title_sort Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil
author Freitas, Ana Cristina
author_facet Freitas, Ana Cristina
Kinas, Paul Gerhard
Martins, Cristiane Cavalcante Albuquerque
Coitinho, Márcia Helena Engel
author_role author
author2 Kinas, Paul Gerhard
Martins, Cristiane Cavalcante Albuquerque
Coitinho, Márcia Helena Engel
author2_role author
author
author
dc.contributor.author.fl_str_mv Freitas, Ana Cristina
Kinas, Paul Gerhard
Martins, Cristiane Cavalcante Albuquerque
Coitinho, Márcia Helena Engel
dc.subject.por.fl_str_mv Abundance estimate
Atlantic Ocean
Breeding ground
Humpback whale
Photo-id
South America
topic Abundance estimate
Atlantic Ocean
Breeding ground
Humpback whale
Photo-id
South America
description Abundance estimates are presented for the humpback whales wintering off Brazil which ‘visit’ a surveyed area off Abrolhos Bank and display fluke-exposing behaviour. The study is based on photo-identification data collected between 1996 and 2000. Chapman-corrected Petersen estimates for all pairs of data result in estimates from 1,948 individuals up to 3,001 with coefficients of variation around 0.25. A more elaborate closed population multiple-recapture maximum-likelihood estimate is 2,393 with 95% profile-likelihood confidence interval (CI=1,924, 3,060). Replacing the closed-population assumption with a population allowed to grow (or decrease) according to some constant rate over the study period, the maximum-likelihood estimate of population size for the year 2000 becomes 3,871 (CI=2,795, 5,542) associated to an estimated annual growth rate of 31% over the study period and in the surveyed area. Although the inclusion of the growth rate results in a less restrictive assumption about population size, it is unclear at this time how to interpret it since the population around the Abrolhos Bank is some (unknown) fraction of whales wintering off Brazil. Alternatively, a fit of Whitehead’s model allowing for emigration and re-immigration gives an estimate of about 3,000 whales (CI=2,500, 3,650).
publishDate 2004
dc.date.none.fl_str_mv 2004
2011-08-25T01:47:25Z
2011-08-25T01:47:25Z
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 FREITAS, Ana et al. Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil. The Journal of Cetacean Research and Management, v. 6, n. 3, p. 225-230, 2004. Disponível em: <http://mardecetaceos.net/media_files/download/Freitasetal2004AbundancdeHumpbackinBrazil.pdf>. Acesso em: 24 ago. 2011.
http://repositorio.furg.br/handle/1/932
identifier_str_mv FREITAS, Ana et al. Abundance of humpback whales on the Abrolhos Bank wintering ground, Brazil. The Journal of Cetacean Research and Management, v. 6, n. 3, p. 225-230, 2004. Disponível em: <http://mardecetaceos.net/media_files/download/Freitasetal2004AbundancdeHumpbackinBrazil.pdf>. Acesso em: 24 ago. 2011.
url http://repositorio.furg.br/handle/1/932
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv reponame:Repositório Institucional da FURG (RI FURG)
instname:Universidade Federal do Rio Grande (FURG)
instacron:FURG
instname_str Universidade Federal do Rio Grande (FURG)
instacron_str FURG
institution FURG
reponame_str Repositório Institucional da FURG (RI FURG)
collection Repositório Institucional da FURG (RI FURG)
repository.name.fl_str_mv Repositório Institucional da FURG (RI FURG) - Universidade Federal do Rio Grande (FURG)
repository.mail.fl_str_mv
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