Evaluation of age criteria in New Zealand stoats ( <i>Mustela erminea</i> ) of known age

Abstract

Abstract Incremental lines in the canine teeth of 20 stoats ( Mustela erminea ) corresponded exactly with known age in 5 males and 7 females marked as young, and with minimum‐known age in 6 males and 2 females marked as adults. The lines are added in autumn (April and May) of each year, beginning when the animals are 6 months old. The correlation is accurate enough to permit determination of the ages of wild‐caught adult stoats of unknown age. Two other techniques used previously (baculum weight, post‐orbital ratio of the skull) are confirmed as accurate but much less precise methods of distinguishing young from adult stoats.