THE COMMUTING SYSTEM OF SERENGETI SPOTTED HYAENAS - HOW A PREDATOR COPES WITH MIGRATORY PREY .3. ATTENDANCE AND MATERNAL-CARE

In the Serengeti, spotted hyaenas spent 46-62% of the year foraging by commuting between their clan's territory and the nearest herds of migratory herbivores. During the first 12 months of their life, cubs were stationed at the communal den and were dependent on milk from their mother ('denning female'). This study assessed the impact of the commuting system on maternal care in terms of den attendance and commuting effort, and its fitness consequences in terms of cub growth and survival. Duration of absence intervals decreased while frequency of maternal visits and cub growth rates increased with prey abundance. Mothers of singletons attended their cubs at the same rate as mothers of twins. Growth rates of singletons were higher than those of twins at each level of prey abundance. Cubs growing at higher long-term rates had a significantly better chance of survival. When migratory herbivores were absent from the clan's territory, denning females visited the den more often than non-denning females and males because the mean duration of their commuting trips was shorter (3-4 days versus 6-10 days). The higher attendance by denning females required an increase in travelling effort by a factor of 2-6-3-2 above the level of non-denning females and males. Because maternal effort was highest when cub growth was at a minimum, maternal fitness would be maximized by commuting as little as possible. © 1993 The Association for the Study of Animal Behaviour. All rights reserved.