Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions
Throughout the range of the Steller sea lion ( Eumetopias jubatus ), nearly all births of full-term pups observed from 1968 to 1998 occurred between 15 May and 15 July. We found significant differences in timing of births between rookeries with the earliest mean date of birth (4 June) at Forrester I...
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fthighwire:oai:open-archive.highwire.org:jmammal:82/4/1047 2023-05-15T18:48:56+02:00 Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions Pitcher, Kenneth W. Burkanov, Vladimir N. Calkins, Donald G. Le Boeuf, Burney J. Mamaev, Evgeny G. Merrick, Richard L. Pendleton, Grey W. 2001-11-01 00:00:00.0 text/html http://jmammal.oxfordjournals.org/cgi/content/short/82/4/1047 https://doi.org/10.1644/1545-1542(2001)082<1047:SATVIT>2.0.CO;2 en eng Oxford University Press http://jmammal.oxfordjournals.org/cgi/content/short/82/4/1047 http://dx.doi.org/10.1644/1545-1542(2001)082<1047:SATVIT>2.0.CO;2 Copyright (C) 2001, Oxford University Press Feature Articles TEXT 2001 fthighwire https://doi.org/10.1644/1545-1542(2001)082<1047:SATVIT>2.0.CO;2 2016-11-16T16:51:50Z Throughout the range of the Steller sea lion ( Eumetopias jubatus ), nearly all births of full-term pups observed from 1968 to 1998 occurred between 15 May and 15 July. We found significant differences in timing of births between rookeries with the earliest mean date of birth (4 June) at Forrester Island, Alaska, and the latest (21 June) at Año Nuevo Island, California. Mean date of birth becomes progressively later both north and south of Forrester Island. Births at individual rookeries were synchronous, with 90% of pups born within a 25-day period. We hypothesize that timing of births at rookeries is determined through selection for time periods when weather conditions are generally favorable for pup survival and when adequate prey items are predictably available near rookeries for lactating females. Temporal differences also were found in mean date of birth at 4 rookeries, with a maximum difference between earliest and latest mean date of birth of 10.2 days at Año Nuevo Island. The most likely explanation for temporal variability at individual rookeries is variable nutritional status of reproductive females. Text Alaska Forrester Island HighWire Press (Stanford University) Forrester Island ENVELOPE(-132.167,-132.167,-74.117,-74.117) |
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HighWire Press (Stanford University) |
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English |
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Feature Articles |
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Feature Articles Pitcher, Kenneth W. Burkanov, Vladimir N. Calkins, Donald G. Le Boeuf, Burney J. Mamaev, Evgeny G. Merrick, Richard L. Pendleton, Grey W. Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions |
topic_facet |
Feature Articles |
description |
Throughout the range of the Steller sea lion ( Eumetopias jubatus ), nearly all births of full-term pups observed from 1968 to 1998 occurred between 15 May and 15 July. We found significant differences in timing of births between rookeries with the earliest mean date of birth (4 June) at Forrester Island, Alaska, and the latest (21 June) at Año Nuevo Island, California. Mean date of birth becomes progressively later both north and south of Forrester Island. Births at individual rookeries were synchronous, with 90% of pups born within a 25-day period. We hypothesize that timing of births at rookeries is determined through selection for time periods when weather conditions are generally favorable for pup survival and when adequate prey items are predictably available near rookeries for lactating females. Temporal differences also were found in mean date of birth at 4 rookeries, with a maximum difference between earliest and latest mean date of birth of 10.2 days at Año Nuevo Island. The most likely explanation for temporal variability at individual rookeries is variable nutritional status of reproductive females. |
format |
Text |
author |
Pitcher, Kenneth W. Burkanov, Vladimir N. Calkins, Donald G. Le Boeuf, Burney J. Mamaev, Evgeny G. Merrick, Richard L. Pendleton, Grey W. |
author_facet |
Pitcher, Kenneth W. Burkanov, Vladimir N. Calkins, Donald G. Le Boeuf, Burney J. Mamaev, Evgeny G. Merrick, Richard L. Pendleton, Grey W. |
author_sort |
Pitcher, Kenneth W. |
title |
Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions |
title_short |
Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions |
title_full |
Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions |
title_fullStr |
Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions |
title_full_unstemmed |
Spatial and Temporal Variation in the Timing of Births of Steller Sea Lions |
title_sort |
spatial and temporal variation in the timing of births of steller sea lions |
publisher |
Oxford University Press |
publishDate |
2001 |
url |
http://jmammal.oxfordjournals.org/cgi/content/short/82/4/1047 https://doi.org/10.1644/1545-1542(2001)082<1047:SATVIT>2.0.CO;2 |
long_lat |
ENVELOPE(-132.167,-132.167,-74.117,-74.117) |
geographic |
Forrester Island |
geographic_facet |
Forrester Island |
genre |
Alaska Forrester Island |
genre_facet |
Alaska Forrester Island |
op_relation |
http://jmammal.oxfordjournals.org/cgi/content/short/82/4/1047 http://dx.doi.org/10.1644/1545-1542(2001)082<1047:SATVIT>2.0.CO;2 |
op_rights |
Copyright (C) 2001, Oxford University Press |
op_doi |
https://doi.org/10.1644/1545-1542(2001)082<1047:SATVIT>2.0.CO;2 |
_version_ |
1766242315324620800 |