Habitat Use, Home Range, and Activity Patterns of Hingeback Tortoises, Kinixys erosa and K. homeana, in Southwestern Cameroon

Home range, habitat use, and seasonal behavior of the Central African forest-dwelling hingeback tortoises Kinixys erosa and K. homeana were quantified by radio tracking 3 translocated and 6 resident individuals for up to 2.3 years in southwestern Cameroon where the two species are sympatric. Individuals of both species varied widely in total and seasonal minimum convex polygon home range estimates (1.1–47.8 ha). Harmonic surface area home range estimates, however, show that most of each tortoise's locations occurred within a relatively small core area representing 5%–25% of an individual's total range. Males of both species had the largest home ranges, and specimens tracked for more than one year showed a decrease in yearly home range size estimates. Considerable overlap of total home ranges but little overlap of core areas exist among individuals of species. Kinixys homeana was located more frequently in forest gaps than was K. erosa, but substantial overlap occurred of habitats and microhabitats used between species. Tortoises tended to gain weight at the beginning and end of the rainy season, and lost weight through the middle of each season.