Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters
For biological populations that form aggregations (or clusters) of individuals, cluster size is an important parameter in line-transect abundance estimation and should be accurately measured. Cluster size in cetaceans has traditionally been represented as the total number of individuals in a group,...
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ftpubmed:oai:pubmedcentral.nih.gov:3938733 2023-05-15T17:03:40+02:00 Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters Bradford, Amanda L. Forney, Karin A. Oleson, Erin M. Barlow, Jay 2014-02-28 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3938733 http://www.ncbi.nlm.nih.gov/pubmed/24587372 https://doi.org/10.1371/journal.pone.0090464 en eng Public Library of Science http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3938733 http://www.ncbi.nlm.nih.gov/pubmed/24587372 http://dx.doi.org/10.1371/journal.pone.0090464 This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. PDM CC0 Research Article Text 2014 ftpubmed https://doi.org/10.1371/journal.pone.0090464 2014-03-09T01:47:48Z For biological populations that form aggregations (or clusters) of individuals, cluster size is an important parameter in line-transect abundance estimation and should be accurately measured. Cluster size in cetaceans has traditionally been represented as the total number of individuals in a group, but group size may be underestimated if group members are spatially diffuse. Groups of false killer whales (Pseudorca crassidens) can comprise numerous subgroups that are dispersed over tens of kilometers, leading to a spatial mismatch between a detected group and the theoretical framework of line-transect analysis. Three stocks of false killer whales are found within the U.S. Exclusive Economic Zone of the Hawaiian Islands (Hawaiian EEZ): an insular main Hawaiian Islands stock, a pelagic stock, and a Northwestern Hawaiian Islands (NWHI) stock. A ship-based line-transect survey of the Hawaiian EEZ was conducted in the summer and fall of 2010, resulting in six systematic-effort visual sightings of pelagic (n = 5) and NWHI (n = 1) false killer whale groups. The maximum number and spatial extent of subgroups per sighting was 18 subgroups and 35 km, respectively. These sightings were combined with data from similar previous surveys and analyzed within the conventional line-transect estimation framework. The detection function, mean cluster size, and encounter rate were estimated separately to appropriately incorporate data collected using different methods. Unlike previous line-transect analyses of cetaceans, subgroups were treated as the analytical cluster instead of groups because subgroups better conform to the specifications of line-transect theory. Bootstrap values (n = 5,000) of the line-transect parameters were randomly combined to estimate the variance of stock-specific abundance estimates. Hawai’i pelagic and NWHI false killer whales were estimated to number 1,552 (CV = 0.66; 95% CI = 479–5,030) and 552 (CV = 1.09; 95% CI = 97–3,123) individuals, respectively. Subgroup structure is an important factor to consider ... Text Killer Whale PubMed Central (PMC) PLoS ONE 9 2 e90464 |
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Research Article Bradford, Amanda L. Forney, Karin A. Oleson, Erin M. Barlow, Jay Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters |
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Research Article |
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For biological populations that form aggregations (or clusters) of individuals, cluster size is an important parameter in line-transect abundance estimation and should be accurately measured. Cluster size in cetaceans has traditionally been represented as the total number of individuals in a group, but group size may be underestimated if group members are spatially diffuse. Groups of false killer whales (Pseudorca crassidens) can comprise numerous subgroups that are dispersed over tens of kilometers, leading to a spatial mismatch between a detected group and the theoretical framework of line-transect analysis. Three stocks of false killer whales are found within the U.S. Exclusive Economic Zone of the Hawaiian Islands (Hawaiian EEZ): an insular main Hawaiian Islands stock, a pelagic stock, and a Northwestern Hawaiian Islands (NWHI) stock. A ship-based line-transect survey of the Hawaiian EEZ was conducted in the summer and fall of 2010, resulting in six systematic-effort visual sightings of pelagic (n = 5) and NWHI (n = 1) false killer whale groups. The maximum number and spatial extent of subgroups per sighting was 18 subgroups and 35 km, respectively. These sightings were combined with data from similar previous surveys and analyzed within the conventional line-transect estimation framework. The detection function, mean cluster size, and encounter rate were estimated separately to appropriately incorporate data collected using different methods. Unlike previous line-transect analyses of cetaceans, subgroups were treated as the analytical cluster instead of groups because subgroups better conform to the specifications of line-transect theory. Bootstrap values (n = 5,000) of the line-transect parameters were randomly combined to estimate the variance of stock-specific abundance estimates. Hawai’i pelagic and NWHI false killer whales were estimated to number 1,552 (CV = 0.66; 95% CI = 479–5,030) and 552 (CV = 1.09; 95% CI = 97–3,123) individuals, respectively. Subgroup structure is an important factor to consider ... |
format |
Text |
author |
Bradford, Amanda L. Forney, Karin A. Oleson, Erin M. Barlow, Jay |
author_facet |
Bradford, Amanda L. Forney, Karin A. Oleson, Erin M. Barlow, Jay |
author_sort |
Bradford, Amanda L. |
title |
Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters |
title_short |
Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters |
title_full |
Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters |
title_fullStr |
Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters |
title_full_unstemmed |
Accounting for Subgroup Structure in Line-Transect Abundance Estimates of False Killer Whales (Pseudorca crassidens) in Hawaiian Waters |
title_sort |
accounting for subgroup structure in line-transect abundance estimates of false killer whales (pseudorca crassidens) in hawaiian waters |
publisher |
Public Library of Science |
publishDate |
2014 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3938733 http://www.ncbi.nlm.nih.gov/pubmed/24587372 https://doi.org/10.1371/journal.pone.0090464 |
genre |
Killer Whale |
genre_facet |
Killer Whale |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3938733 http://www.ncbi.nlm.nih.gov/pubmed/24587372 http://dx.doi.org/10.1371/journal.pone.0090464 |
op_rights |
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. |
op_rightsnorm |
PDM CC0 |
op_doi |
https://doi.org/10.1371/journal.pone.0090464 |
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PLoS ONE |
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9 |
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2 |
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e90464 |
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