New Zealand fur seals (Arctocephalus 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.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.