Wh. Oosthuizen et Mn. Bester, COMPARISON OF AGE-DETERMINATION TECHNIQUES FOR KNOWN-AGE CAPE FUR SEALS, South African journal of zoology, 32(4), 1997, pp. 106-111
Known-age teeth were used to validate age determination techniques for
the Cape fur seal (Arctocephalus pusillus pusillus). Thin sectioning
and staining of decalcified teeth produced the poorest age estimates.
For etched half canines, only upper canines could be used to estimate
age with good results, and coating improved the accuracy. Scanning ele
ctron microscopy produced poor accuracy in age estimation. External ri
dges reflected age accurately only in younger age classes and should o
nly be used to verify counts of internal growth layer groups, or when
rapid, preliminary estimates of age are necessary. This study has high
lighted the importance of comparing different age determination techni
ques and validating such techniques with known-age animals. The reliab
ility with which age can be estimated for the Cape fur seal has also b
een improved.