The feasibility of using body proportions in Western Australian varanids (Varanus) as a method for determining a specimen's sex
Western Australian Museum
Faculty of Business and Public Management
School of Marketing, Tourism and Leisure
The literature suggests that varanids are sexually dimorphic based on an array of morphometric variables. Brana (1996) reports that for lacertid lizards, size-corrected abdominal length is always larger in females and head lengths are always larger in males. Thompson and Withers (1997) reported a similar trend for some Western Australian varanids. This study examined the possibility of using a ratio of abdominal length and head length to determine the sex of varanids caught in the field. Although there are statistically significant differences in the mean ratio of abdominal length and head length for males and females for seven species of varanids in the subgenus Odatria, overlap in the ratio between males and females is too large for this to be a useful measure by itself. This ratio might, however, be useful when combined with other techniques (such as everting hemipenes) to improve the probability of determining the sex of wild-caught specimens. Ratios of abdominal length and head length for varanids in the subgenus Varanus do not differ between sexes.