Méthodes de détermination de l’âge chez le chat haret des îles Kerguelen

The different methods of age determination used in the study of mammals are compared, using a sample (N = 292) of feral cats (Felis catus L.) from the Kerguelen islands as an example. “Skeletal growth marks” in bone and cementum have already been used successfully on several species of Mammals. In our case, emphasis has been especially put on the critical use and discussion of these methods of “skeletochronology”. No direct comparisons with animals of known age being possible, we had to rely on circumstancial evidence to demonstrate the value of the method. Bone tissue (jaw) and dental cementum were both used and compared. A critical study of the histological patterns shown by the tissues allows a functionnal interpretation. Wide zones of fast deposited tissues (warm season deposits) alternate with narrow annuli (narrow “rest lines” here called LAC = lignes d’arrêt de croissance) which are cool season marks. The results have been cheked against other methods of age determination, such as body weight, dry weight of the eye lens, and tooth succession. A good correlation has been found between the results from these different techniques. Seven age groups have been found and the best age resolution for adults fall to six months.