Dentition and age determination of the Warthog <i>Phacochoerus aethiopicus</i> in Zululand, South Africa

Abstract

Age-specific stages of tooth replacement, eruption and attrition are described for warthogs shot during population control in Zululand. Patterns of tooth replacement and eruption allowed reasonably accurate age determination up to 24 months, whereafter 2-3 year old warthogs could generally be distinguished from older individuals by the relative growth of their third molars. Although stages of wear and loss of the teeth, especially the three molars, were associated with broad age classes, age of adult warthogs may be determined more precisely by counting cementum annuli in sectioned incisor teeth. However, cementum annuli were insufficiently distinctive to permit age estimation in approximately 33 of sections, reflecting particularly variation in intensity and clarity of staining and splitting and merging of rest lines. The use of eye lens dry mass and tusk length: snout width ratios as indices of age was also evaluated. Eye lens dry mass became increasingly unreliable for predicting age beyond 24 months. Considering males and females separately, tusk length: snout width ratios for yearling, 2-3 year old and 3-4 year old warthogs were reasonably distinctive, but subsequent overlap was apparently unfavourable for reliable differentiation of year classes among older warthogs. Body size and tusk * development criteria for distinguishing between three age classes ofwarthogs in the field are presented.