Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli )
The reproductive performance of tagged Weddell seals (Leptonychotes weddelli) was monitored at McMurdo Sound, Antarctica, from 1970 to 1984. An age-specific reproductive schedule revealed the major onset of pupping at age 6 years, and a mean age of first birth of 7.1 years. The average asymptotic pu...
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1987
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crcansciencepubl:10.1139/z87-173 2023-12-17T10:21:29+01:00 Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli ) Testa, J. Ward 1987 http://dx.doi.org/10.1139/z87-173 http://www.nrcresearchpress.com/doi/pdf/10.1139/z87-173 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Zoology volume 65, issue 5, page 1091-1099 ISSN 0008-4301 1480-3283 Animal Science and Zoology Ecology, Evolution, Behavior and Systematics journal-article 1987 crcansciencepubl https://doi.org/10.1139/z87-173 2023-11-19T13:38:42Z The reproductive performance of tagged Weddell seals (Leptonychotes weddelli) was monitored at McMurdo Sound, Antarctica, from 1970 to 1984. An age-specific reproductive schedule revealed the major onset of pupping at age 6 years, and a mean age of first birth of 7.1 years. The average asymptotic pupping rate of 0.61 is reached by age 10. The cost of pupping in a given year is reflected in a 0.05 drop in the probability of pupping the following year. This cost is not evident in females over 7 years old, suggesting that postweaning condition affects newly mature females more than those that are fully mature. Annual adult reproductive rates ranged from 0.46 to 0.79, with a possible periodicity of 5 to 6 years. Simulations were conducted to determine the impact on reproductive estimates of sighting biases associated with seals having had at least one pup (Parous) or having pupped that season (With-Pup). Age at first reproduction as deduced from an age-specific pupping schedule is strongly affected by both forms of sighting bias, but bias in sighting Parous females was the more important. Estimates of adult reproduction were affected minimally. Comparisons of reproductive estimates with those of Weddell seals at Signy Island are discussed with regard to the effects of sighting biases. Article in Journal/Newspaper Antarc* Antarctica Leptonychotes weddelli McMurdo Sound Signy Island Weddell Seals Canadian Science Publishing (via Crossref) McMurdo Sound Weddell Signy Island ENVELOPE(-45.595,-45.595,-60.708,-60.708) Canadian Journal of Zoology 65 5 1091 1099 |
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Open Polar |
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Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
spellingShingle |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics Testa, J. Ward Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli ) |
topic_facet |
Animal Science and Zoology Ecology, Evolution, Behavior and Systematics |
description |
The reproductive performance of tagged Weddell seals (Leptonychotes weddelli) was monitored at McMurdo Sound, Antarctica, from 1970 to 1984. An age-specific reproductive schedule revealed the major onset of pupping at age 6 years, and a mean age of first birth of 7.1 years. The average asymptotic pupping rate of 0.61 is reached by age 10. The cost of pupping in a given year is reflected in a 0.05 drop in the probability of pupping the following year. This cost is not evident in females over 7 years old, suggesting that postweaning condition affects newly mature females more than those that are fully mature. Annual adult reproductive rates ranged from 0.46 to 0.79, with a possible periodicity of 5 to 6 years. Simulations were conducted to determine the impact on reproductive estimates of sighting biases associated with seals having had at least one pup (Parous) or having pupped that season (With-Pup). Age at first reproduction as deduced from an age-specific pupping schedule is strongly affected by both forms of sighting bias, but bias in sighting Parous females was the more important. Estimates of adult reproduction were affected minimally. Comparisons of reproductive estimates with those of Weddell seals at Signy Island are discussed with regard to the effects of sighting biases. |
format |
Article in Journal/Newspaper |
author |
Testa, J. Ward |
author_facet |
Testa, J. Ward |
author_sort |
Testa, J. Ward |
title |
Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli ) |
title_short |
Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli ) |
title_full |
Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli ) |
title_fullStr |
Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli ) |
title_full_unstemmed |
Long-term reproductive patterns and sighting bias in Weddell seals ( Leptonychotes weddelli ) |
title_sort |
long-term reproductive patterns and sighting bias in weddell seals ( leptonychotes weddelli ) |
publisher |
Canadian Science Publishing |
publishDate |
1987 |
url |
http://dx.doi.org/10.1139/z87-173 http://www.nrcresearchpress.com/doi/pdf/10.1139/z87-173 |
long_lat |
ENVELOPE(-45.595,-45.595,-60.708,-60.708) |
geographic |
McMurdo Sound Weddell Signy Island |
geographic_facet |
McMurdo Sound Weddell Signy Island |
genre |
Antarc* Antarctica Leptonychotes weddelli McMurdo Sound Signy Island Weddell Seals |
genre_facet |
Antarc* Antarctica Leptonychotes weddelli McMurdo Sound Signy Island Weddell Seals |
op_source |
Canadian Journal of Zoology volume 65, issue 5, page 1091-1099 ISSN 0008-4301 1480-3283 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/z87-173 |
container_title |
Canadian Journal of Zoology |
container_volume |
65 |
container_issue |
5 |
container_start_page |
1091 |
op_container_end_page |
1099 |
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1785535168103055360 |