Growth and age determination in the hyrax <i>Procavia capensis</i>

Abstract

Growth and age determination were studied in known age captive hyrax by measuring the animals monthly for three years and killing groups at ages 12,24 and 36 months. Ten body measurements and five skull measurements were used as ageing criteria using multiple regression and a predictive equation. Age (months) = 0,0593 Length + 0,0444 Girth + 0,01117 Headlength - 20,652 was developed for both sexes. Tooth eruption and wear, dental annulli and eyelenses were also investigated and an ageing schedule was developed using tooth eruption and wear. Cementum annulli were shown to be a valid means of ageing up to 36 months and probably up to at least eight years. Eyelenses are not an effective ageing method. Growth in the hyrax is slow and Von Bertalanffy growth coefficients are similar to those in the elephant.