Movement patterns and home range of Cape clawless otters (Aonyx capensis), affected by high food density patches


All correspondence to present address: M. J. Somers Applied Behaviour and Ecology Laboratory, Department of Zoology, University of Transkei, Private Bag X1, 5117 UNITRA, South Africa. E-mail:


To determine the effects of their movement patterns, seven Cape clawless otters Aonyx capensis were caught in two rivers and radio-tracked between 1993 and 1995. Total range length varied from 4.9 to 54.1 km and core length from 0.2 to 9.8 km. Total area of water used varied between 4.9 and 1062.5 ha, and core areas from 1.1 to 138.9 ha. As predicted using the resource dispersion hypothesis, total home-range length was correlated with mean reed bed (high food density patch) nearest neighbour distance. The pattern of home-range use by females was suggestive of territoriality. Male Cape clawless otters had overlapping home ranges, both with other males and with females.