THE COMMUTING SYSTEM OF SERENGETI SPOTTED HYAENAS - HOW A PREDATOR COPES WITH MIGRATORY PREY .2. INTRUSION PRESSURE AND COMMUTERS SPACE USE

In the Serengeti, Tanzania, spotted hyaenas, Crocuta crocuta Erxleben, regularly left their clan's territory to feed on the nearest migratory herds ('commuting trips'). The mean commuting distance was 40 km. Commuting locations matched the movements of the migratory herds throughout the year. The distribution of commuters was compatible with the hypotheses that commuters (1) minimized contact with resident clans and (2) utilized areas where they were assured of locating migratory herds. The proportion of clan members commuting declined as prey abundance in the clan's territory increased. Territories were visited by non-residents (commuters) throughout the year but the number of foraging commuters increased substantially when large migratory herds entered a territory. During encounters between residents and intruders, residents adjusted their behaviour according to the context of the encounter: Residents ignored commuters 'in transit', responded aggressively to commuters at kills, and engaged in prolonged clashes with neighbouring clans. A comparison with the space use systems of other carnivores indicates that the commuting system of spotted hyaenas in the Serengeti is unique. It is hypothesized that the development of the commuting system was contingent on several adaptive behavioural, morphological and physiological specializations. © 1993 The Association for the Study of Animal Behaviour. All rights reserved.