Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies
Our aim was to develop a method for estimating the number of animals using a single site in an asynchronous species, meaning that not all animals are present at once so that no one count captures the entire population. This is a common problem in seasonal breeders, and in northern elephant seals, we...
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ftdoajarticles:oai:doaj.org/article:553a71a9e69e4444bbd49e04f1d0db78 2023-05-15T16:05:21+02:00 Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies Richard Condit Sarah G. Allen Daniel P. Costa Sarah Codde P. Dawn Goley Burney J. Le Boeuf Mark S. Lowry Patricia Morris 2022-01-01T00:00:00Z https://doaj.org/article/553a71a9e69e4444bbd49e04f1d0db78 EN eng Public Library of Science (PLoS) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8786122/?tool=EBI https://doaj.org/toc/1932-6203 1932-6203 https://doaj.org/article/553a71a9e69e4444bbd49e04f1d0db78 PLoS ONE, Vol 17, Iss 1 (2022) Medicine R Science Q article 2022 ftdoajarticles 2022-12-31T04:11:46Z Our aim was to develop a method for estimating the number of animals using a single site in an asynchronous species, meaning that not all animals are present at once so that no one count captures the entire population. This is a common problem in seasonal breeders, and in northern elephant seals, we have a model for quantifying asynchrony at the Año Nuevo colony. Here we test the model at several additional colonies having many years of observations and demonstrate how it can account for animals not present on any one day. This leads to correction factors that yield total population from any single count throughout a season. At seven colonies in California for which we had many years of counts of northern elephant seals, we found that female arrival date varied < 2 days between years within sites and by < 5 days between sites. As a result, the correction factor for any one day was consistent, and at each colony, multiplying a female count between 26 and 30 Jan by 1.15 yielded an estimate of total population size that minimized error. This provides a method for estimating the female population size at colonies not yet studied. Our method can produce population estimates with minimal expenditure of time and resources and will be applicable to many seasonal species with asynchronous breeding phenology, particularly colonial birds and other pinnipeds. In elephant seals, it will facilitate monitoring the population over its entire range. Article in Journal/Newspaper Elephant Seal Elephant Seals Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
Medicine R Science Q |
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Medicine R Science Q Richard Condit Sarah G. Allen Daniel P. Costa Sarah Codde P. Dawn Goley Burney J. Le Boeuf Mark S. Lowry Patricia Morris Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies |
topic_facet |
Medicine R Science Q |
description |
Our aim was to develop a method for estimating the number of animals using a single site in an asynchronous species, meaning that not all animals are present at once so that no one count captures the entire population. This is a common problem in seasonal breeders, and in northern elephant seals, we have a model for quantifying asynchrony at the Año Nuevo colony. Here we test the model at several additional colonies having many years of observations and demonstrate how it can account for animals not present on any one day. This leads to correction factors that yield total population from any single count throughout a season. At seven colonies in California for which we had many years of counts of northern elephant seals, we found that female arrival date varied < 2 days between years within sites and by < 5 days between sites. As a result, the correction factor for any one day was consistent, and at each colony, multiplying a female count between 26 and 30 Jan by 1.15 yielded an estimate of total population size that minimized error. This provides a method for estimating the female population size at colonies not yet studied. Our method can produce population estimates with minimal expenditure of time and resources and will be applicable to many seasonal species with asynchronous breeding phenology, particularly colonial birds and other pinnipeds. In elephant seals, it will facilitate monitoring the population over its entire range. |
format |
Article in Journal/Newspaper |
author |
Richard Condit Sarah G. Allen Daniel P. Costa Sarah Codde P. Dawn Goley Burney J. Le Boeuf Mark S. Lowry Patricia Morris |
author_facet |
Richard Condit Sarah G. Allen Daniel P. Costa Sarah Codde P. Dawn Goley Burney J. Le Boeuf Mark S. Lowry Patricia Morris |
author_sort |
Richard Condit |
title |
Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies |
title_short |
Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies |
title_full |
Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies |
title_fullStr |
Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies |
title_full_unstemmed |
Estimating population size when individuals are asynchronous: A model illustrated with northern elephant seal breeding colonies |
title_sort |
estimating population size when individuals are asynchronous: a model illustrated with northern elephant seal breeding colonies |
publisher |
Public Library of Science (PLoS) |
publishDate |
2022 |
url |
https://doaj.org/article/553a71a9e69e4444bbd49e04f1d0db78 |
genre |
Elephant Seal Elephant Seals |
genre_facet |
Elephant Seal Elephant Seals |
op_source |
PLoS ONE, Vol 17, Iss 1 (2022) |
op_relation |
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8786122/?tool=EBI https://doaj.org/toc/1932-6203 1932-6203 https://doaj.org/article/553a71a9e69e4444bbd49e04f1d0db78 |
_version_ |
1766401244392325120 |