Age determination of Cape porcupines, Hystrix africaeaustralis

Abstract

Attempts to determine the absolute age of free-ranging porcupines based on counts of cementum and periosteal lines, age-related changes In eye lens weight, sequential pattern of tooth eruption and replacement, and tooth attrition are described. Variation due to ramification and absorption of cementum and periosteal lines resulted in counts of these lines being unreliable indicators of age. Variation in counts of cementum lines apparently results from continual growth of the hypsodontic open-rooted premolars and molars. Heteroscadasticity resulted in the relationship between age and lens weight being unreliable for predicting age. Consistency In the age at which maxillary molars erupt and premolars are replaced, as well as the wear pattern of the occlusal surfaces, provide a method for distinguishing nine dental age classes. Chronological age, based on observations on captive porcupines could be accurately assigned to six of these.