A preliminary radiotracking study of movements, activity patterns and habitat use of free-ranging Gaboon Vipers, Bitis gabonica

Radiotelemetry was employed to study daily movements, activity patterns, ma crohabitat use, and substratum selection of four Gaboon vipers (Bitis gabon ica), two adult males and two adult females. The study was carried out duri ng the dry season (1-20 March, 1998) in south-eastern Nigeria. Transmitters , weighing approximately 4 g, were internally implanted. Gaboon vipers spen t considerable time inactive below-ground. There was considerable nocturnal activity in the open in three of four specimens. and considerable above-gr ound activity during the early morning hours in all the four radiotracked s pecimens. These vipers showed a significant preference for the clearings in side dryland rainforest patches, and avoided cultivated lands. Males used a wider spectrum of macrohabitats than females, these latter being confined almost exclusively to dry forest clearings. Home-ranges, calculated by mini mum convex polygon method, averaged 1.6 ha in the males and 0.8 ha in the f emales. Average daily distances moved were significantly higher in males th an in females. In both sexes, average daily distances moved were significan tly higher during night hours than during daylight hours. Courtships, matin gs, and sexual combats between males were sometimes observed during the stu dy period. These vipers used sometimes the termite nests as shelters.