Earlier pupping in harbour seals, Phoca vitulina
The annual reproductive cycle of most seal species is characterized by a tight synchrony of births. Typically, timing of birth shows little inter-annual variation. Here, however we show that harbour seals Phoca vitulina from the Wadden Sea (southeast North Sea) have shortened their yearly cycle, mov...
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Online Access: | http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001384 http://www.ncbi.nlm.nih.gov/pubmed/20591851 https://doi.org/10.1098/rsbl.2010.0468 |
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ftpubmed:oai:pubmedcentral.nih.gov:3001384 2023-05-15T17:58:52+02:00 Earlier pupping in harbour seals, Phoca vitulina Reijnders, Peter J. H. Brasseur, Sophie M. J. M. Meesters, Erik H. W. G. 2010-12-23 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001384 http://www.ncbi.nlm.nih.gov/pubmed/20591851 https://doi.org/10.1098/rsbl.2010.0468 en eng The Royal Society http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001384 http://www.ncbi.nlm.nih.gov/pubmed/20591851 http://dx.doi.org/10.1098/rsbl.2010.0468 © 2010 The Royal Society Population Ecology Text 2010 ftpubmed https://doi.org/10.1098/rsbl.2010.0468 2013-09-03T08:42:40Z The annual reproductive cycle of most seal species is characterized by a tight synchrony of births. Typically, timing of birth shows little inter-annual variation. Here, however we show that harbour seals Phoca vitulina from the Wadden Sea (southeast North Sea) have shortened their yearly cycle, moving parturition to earlier dates since the early 1970s. Between 1974 and 2009, the birth date of harbour seals shifted on average by −0.71 d yr−1, three and a half weeks (25 days) earlier, in the Dutch part of the Wadden Sea. Pup counts available for other parts of the Wadden Sea were analysed, showing a similar shift. To elucidate potential mechanism(s) for this shift in pupping phenology, possible changes in population demography, changes in maternal life-history traits and variations in environmental conditions were examined. It was deduced that the most likely mechanism was a shortening of embryonic diapause. We hypothesize that this could have been facilitated by an improved forage base, e.g. increase of small fishes, attributable to overfishing of large predator fishes and size-selective fisheries. Text Phoca vitulina PubMed Central (PMC) Biology Letters 6 6 854 857 |
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Open Polar |
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PubMed Central (PMC) |
op_collection_id |
ftpubmed |
language |
English |
topic |
Population Ecology |
spellingShingle |
Population Ecology Reijnders, Peter J. H. Brasseur, Sophie M. J. M. Meesters, Erik H. W. G. Earlier pupping in harbour seals, Phoca vitulina |
topic_facet |
Population Ecology |
description |
The annual reproductive cycle of most seal species is characterized by a tight synchrony of births. Typically, timing of birth shows little inter-annual variation. Here, however we show that harbour seals Phoca vitulina from the Wadden Sea (southeast North Sea) have shortened their yearly cycle, moving parturition to earlier dates since the early 1970s. Between 1974 and 2009, the birth date of harbour seals shifted on average by −0.71 d yr−1, three and a half weeks (25 days) earlier, in the Dutch part of the Wadden Sea. Pup counts available for other parts of the Wadden Sea were analysed, showing a similar shift. To elucidate potential mechanism(s) for this shift in pupping phenology, possible changes in population demography, changes in maternal life-history traits and variations in environmental conditions were examined. It was deduced that the most likely mechanism was a shortening of embryonic diapause. We hypothesize that this could have been facilitated by an improved forage base, e.g. increase of small fishes, attributable to overfishing of large predator fishes and size-selective fisheries. |
format |
Text |
author |
Reijnders, Peter J. H. Brasseur, Sophie M. J. M. Meesters, Erik H. W. G. |
author_facet |
Reijnders, Peter J. H. Brasseur, Sophie M. J. M. Meesters, Erik H. W. G. |
author_sort |
Reijnders, Peter J. H. |
title |
Earlier pupping in harbour seals, Phoca vitulina |
title_short |
Earlier pupping in harbour seals, Phoca vitulina |
title_full |
Earlier pupping in harbour seals, Phoca vitulina |
title_fullStr |
Earlier pupping in harbour seals, Phoca vitulina |
title_full_unstemmed |
Earlier pupping in harbour seals, Phoca vitulina |
title_sort |
earlier pupping in harbour seals, phoca vitulina |
publisher |
The Royal Society |
publishDate |
2010 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001384 http://www.ncbi.nlm.nih.gov/pubmed/20591851 https://doi.org/10.1098/rsbl.2010.0468 |
genre |
Phoca vitulina |
genre_facet |
Phoca vitulina |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3001384 http://www.ncbi.nlm.nih.gov/pubmed/20591851 http://dx.doi.org/10.1098/rsbl.2010.0468 |
op_rights |
© 2010 The Royal Society |
op_doi |
https://doi.org/10.1098/rsbl.2010.0468 |
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Biology Letters |
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6 |
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6 |
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854 |
op_container_end_page |
857 |
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1766167581231677440 |