Feeding ecology, reproduction and sexual dimorphism in the colubrid snake Crotaphopeltis hotamboeia in southern Africa

Abstract

We examined museum specimens to quantify diet, reproductive cycles and sexual dimorphism in body size of the colubrid snake Crotaphopeltis hotamboeia. Females attain sexual maturity at approximately 300 mm snout‐vent length (SVL) and males at approximately 240 mm SVL. Females grow larger than males (maximum SVLs of 830 vs 700 mm SVL), and also have longer and wider heads and wider bodies than do males of the same body length. Males have relatively longer tails than females, but eye size relative to head length shows no sexual dimorphism. Both sexes breed each year. Females commence vitellogenesis in late winter (September) and oviposit from October to January. Clutch size ranged from four to 12 eggs with a mean of 7.58 and was highly correlated with female SVL. The testes of adult males are turgid throughout the year, suggesting a prolonged mating season. Of 73 prey items recorded, 97% were anurans. Six anuran families were represented among the prey items, but bufonids (39%), ranids (29%) and microhylids (25%) comprised most of the 51 anuran food items identified to genus. Larger snakes ate larger prey items, in terms of SVL as well as mass. However, the snake's sex and age (adult vs juvenile) did not affect prey type. Bufonids, microhylids and ranids were consumed by snakes of all ages and both sexes, and were eaten all year except during mid‐winter (July and August).