Determining a correction factor for aerial surveys of harbor seals in California
Abstract Counts of pinnipeds provide a minimal estimate of population size because some unknown proportion of individuals is in the water during surveys. We determined a correction factor (CF) for Pacific harbor seals ( Phoca vitulina richardii ) by estimating the proportion ashore of 180 seals tagg...
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crwiley:10.1111/j.1748-7692.2010.00446.x 2023-12-03T10:29:05+01:00 Determining a correction factor for aerial surveys of harbor seals in California Harvey, James T. Goley, Dawn 2011 http://dx.doi.org/10.1111/j.1748-7692.2010.00446.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2010.00446.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2010.00446.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Marine Mammal Science volume 27, issue 4, page 719-735 ISSN 0824-0469 1748-7692 Aquatic Science Ecology, Evolution, Behavior and Systematics journal-article 2011 crwiley https://doi.org/10.1111/j.1748-7692.2010.00446.x 2023-11-09T14:03:06Z Abstract Counts of pinnipeds provide a minimal estimate of population size because some unknown proportion of individuals is in the water during surveys. We determined a correction factor (CF) for Pacific harbor seals ( Phoca vitulina richardii ) by estimating the proportion ashore of 180 seals tagged with flipper‐mounted radio tags throughout California. The mean proportions of tagged individuals ashore during four complete surveys in 2004 were not different between central and northern California ( F = 1.85, P = 0.18) or between sexes ( F = 0.57, P = 0.45), but a lesser proportion of weaners was ashore than subadults or adults ( F = 7.97, P = 0.001), especially in northern California. The CF calculated for the statewide census of harbor seals was 1.65, using transmitters operating during the survey ( n = 114). Using a mark‐recapture estimator for tag survival ( phi ) and the four telemetry surveys the mean CF for central and northern California was 1.54 ± 0.38 (95% CI). A CF for southern California of 2.86 was based on a single survey. Using the mean CF of 1.54 and a statewide count in 2009 we estimated 30,196 (95% CI = 22,745–37,647) harbor seals in California. Article in Journal/Newspaper Phoca vitulina Wiley Online Library (via Crossref) Pacific Marine Mammal Science 27 4 719 735 |
institution |
Open Polar |
collection |
Wiley Online Library (via Crossref) |
op_collection_id |
crwiley |
language |
English |
topic |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Aquatic Science Ecology, Evolution, Behavior and Systematics Harvey, James T. Goley, Dawn Determining a correction factor for aerial surveys of harbor seals in California |
topic_facet |
Aquatic Science Ecology, Evolution, Behavior and Systematics |
description |
Abstract Counts of pinnipeds provide a minimal estimate of population size because some unknown proportion of individuals is in the water during surveys. We determined a correction factor (CF) for Pacific harbor seals ( Phoca vitulina richardii ) by estimating the proportion ashore of 180 seals tagged with flipper‐mounted radio tags throughout California. The mean proportions of tagged individuals ashore during four complete surveys in 2004 were not different between central and northern California ( F = 1.85, P = 0.18) or between sexes ( F = 0.57, P = 0.45), but a lesser proportion of weaners was ashore than subadults or adults ( F = 7.97, P = 0.001), especially in northern California. The CF calculated for the statewide census of harbor seals was 1.65, using transmitters operating during the survey ( n = 114). Using a mark‐recapture estimator for tag survival ( phi ) and the four telemetry surveys the mean CF for central and northern California was 1.54 ± 0.38 (95% CI). A CF for southern California of 2.86 was based on a single survey. Using the mean CF of 1.54 and a statewide count in 2009 we estimated 30,196 (95% CI = 22,745–37,647) harbor seals in California. |
format |
Article in Journal/Newspaper |
author |
Harvey, James T. Goley, Dawn |
author_facet |
Harvey, James T. Goley, Dawn |
author_sort |
Harvey, James T. |
title |
Determining a correction factor for aerial surveys of harbor seals in California |
title_short |
Determining a correction factor for aerial surveys of harbor seals in California |
title_full |
Determining a correction factor for aerial surveys of harbor seals in California |
title_fullStr |
Determining a correction factor for aerial surveys of harbor seals in California |
title_full_unstemmed |
Determining a correction factor for aerial surveys of harbor seals in California |
title_sort |
determining a correction factor for aerial surveys of harbor seals in california |
publisher |
Wiley |
publishDate |
2011 |
url |
http://dx.doi.org/10.1111/j.1748-7692.2010.00446.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.2010.00446.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.2010.00446.x |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Phoca vitulina |
genre_facet |
Phoca vitulina |
op_source |
Marine Mammal Science volume 27, issue 4, page 719-735 ISSN 0824-0469 1748-7692 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1748-7692.2010.00446.x |
container_title |
Marine Mammal Science |
container_volume |
27 |
container_issue |
4 |
container_start_page |
719 |
op_container_end_page |
735 |
_version_ |
1784254229656895488 |