Diet of sympatric Gaboon Vipers (Bitis gabonica) and Nose‐horned Vipers (Bitis nasicornis) in southern Nigeria

Abstract

The stomach content of 524 Gaboon Vipers, Bitis gabonica gabonica (53 subadults, 222 males and 249 females) and 392 Nose‐horned Vipers, Bitis nasicornis (48 subadults, 163 males and 161 females), from a number of forest‐plantation mosaic areas of southern Nigeria (West Africa) were recorded. Adult sex ratio was close to 1:1 in both species. In both Gaboon and Nose‐horned vipers, mean SVL of females significantly exceeded that of males. 30.7% of the total sample of Gaboon Vipers and 26% of the total sample of Nose‐horned Vipers contained identifiable food in the stomach. The stomachs of gravid females of both species never contained food. The stomach contents of the Gaboon Vipers consisted mainly of small mammals, followed by birds, lizards and, occasonally frogs. Males and females had similar diets. The diet of subadults differed from that of adults in that there were significantly more newborn mice and more lizards consumed. Nose‐horned Vipers also fed mainly upon small mammals, but amphibians were also eaten. Males and females had similar diets, and the diet of subadults differed from that of adults and consisted largely of newborn mice.