Influences on fecundity in Australian fur seals (Arctocephalus pusillus doriferus)

Gibbens, John, Parry, Laura J. and Arnould, John P. Y 2010, Influences on fecundity in Australian fur seals (Arctocephalus pusillus doriferus), Journal of mammalogy, vol. 91, no. 2, pp. 510-518.

Attached Files
Name Description MIMEType Size Downloads

Title Influences on fecundity in Australian fur seals (Arctocephalus pusillus doriferus)
Formatted title Influences on fecundity in Australian fur seals (Arctocephalus pusillus doriferus)
Author(s) Gibbens, John
Parry, Laura J.
Arnould, John P. Y
Journal name Journal of mammalogy
Volume number 91
Issue number 2
Start page 510
End page 518
Total pages 9
Publisher American Society of Mammalogists
Place of publication Lawrence, Kan.
Publication date 2010-04
ISSN 0022-2372
1545-1542
Keyword(s) Australian fur seal
birth
fecundity
influences
otariid
pinniped
pregnancy
progesterone
rates
reproduction
Summary Recovery of the Australian fur seal (Arctocephalus pusillus doriferus) population has been slower than that of other fur seals, perhaps due to nutritional constraints on fecundity. However, the population doubled in recent decades, suggesting that reproductive rates may have changed. Pregnancy rates and birthrates were estimated and the influences of maternal age, size, condition, and lactation status were investigated over 3 consecutive breeding seasons (2003–2005). Mid-gestation pregnancy rate, estimated from plasma progesterone concentrations, was 84% ± 3% (mean ± SE) and was negatively influenced only by age (P< 0.001). Birthrate, estimated from observations of females with newborn offspring during the breeding season, was 53% 6 3% (mean ± SE) and was influenced negatively by lactation status (P = 0.035). The difference between pregnancy rates and birthrates suggests that a high degree of late-gestation abortion occurs, especially in younger females. Lactation status was not influenced by any variables, and the high rate (86% ± 2%; mean ± SE) suggests that many offspring are suckled beyond the typical weaning period. Although relationships between reproductive rates and body condition were not found, the results are consistent with a nutritional stress hypothesis. The recent increase in population growth is not due to increased fecundity, which remains low compared to other otariids. Paradoxically, high pregnancy rates were observed in young females (3 years), suggesting that rapid maturity is adaptive for benthic foragers.
Language eng
Field of Research 060207 Population Ecology
060205 Marine and Estuarine Ecology (incl Marine Ichthyology)
Socio Economic Objective 960808 Marine Flora, Fauna and Biodiversity
HERDC Research category C1 Refereed article in a scholarly journal
HERDC collection year 2010
Copyright notice ©2010, American Society of Mammalogists
Persistent URL http://hdl.handle.net/10536/DRO/DU:30031567

Document type: Journal Article
Collection: School of Life and Environmental Sciences
Connect to link resolver
 
Unless expressly stated otherwise, the copyright for items in DRO is owned by the author, with all rights reserved.

Versions
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 9 times in TR Web of Science
Scopus Citation Count Cited 10 times in Scopus
Google Scholar Search Google Scholar
Access Statistics: 302 Abstract Views, 2 File Downloads  -  Detailed Statistics
Created: Thu, 09 Dec 2010, 15:56:19 EST by Teresa Treffry

Every reasonable effort has been made to ensure that permission has been obtained for items included in DRO. If you believe that your rights have been infringed by this repository, please contact drosupport@deakin.edu.au.