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Age and reproductive maturity of New Zealand fur seals (Arctocephalus forsteri) in southern Australia


McKenzie, J and Page, B and Shaughnessy, PD and Hindell, MA, Age and reproductive maturity of New Zealand fur seals (Arctocephalus forsteri) in southern Australia, Journal of Mammalogy, 88, (3) pp. 639-648. ISSN 0022-2372 (2007) [Refereed Article]

DOI: doi:10.1644/06-MAMM-A-150R1.1


New Zealand fur seals (Arctocehalus forsteri) are common in the Australian-New Zealand region, but vital demographic data are lacking. Accurate determination of the age of individuals is critical to the study of age-specific life-history parameters. A cross-sectional sample of female and male New Zealand fur seals was caught and animals were individually marked on Kangaroo Island, South Australia, between 2000 and 2003. Seals were aged through examination of a postcanine tooth, which was removed from each animal. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known age. Indirect methods of assessing reproductive maturity based on characteristics of mammary teats indicated that females 1st gave birth between 4 and 8 years of age, with an average age at reproductive maturity (ARM) of 5 years. No females were observed to breed beyond 22 years. Age of 1st territory tenure in males ranged from 8 to 10 years. Variation in ARM between individuals appears to be related in part to body size and condition. Classification of mammary teat status in combination with techniques for aging live animals provided a means of assessing ARM in the absence of extensive longitudinal data. © 2007 American Society of Mammalogists.

Item Details

Item Type:Refereed Article
Research Division:Environmental Sciences
Research Group:Environmental Science and Management
Research Field:Wildlife and Habitat Management
Objective Division:Environment
Objective Group:Ecosystem Assessment and Management
Objective Field:Ecosystem Assessment and Management of Antarctic and Sub-Antarctic Environments
UTAS Author:Hindell, MA (Professor Mark Hindell)
ID Code:50772
Year Published:2007
Web of Science® Times Cited:12
Deposited By:Zoology
Deposited On:2007-08-01
Last Modified:2011-11-08

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