ABSTRACT

Comparisons between monkey and ape behavior have also been difficult, since Carpenter's gibbon study (1940) is the only long term study of an ape that has previously been available. This Asiatic brachiator is as highly specialized for arboreal life as the baboon-macaques are for life on the ground. If the monkeys and apes are arranged along a continuum with those that are terrestrially adapted at one pole and those with specialized arboreal adaptations at the other (Fig. I), it is clear that long-term naturalistic observations have been

confined almost entirely to species lying at the two extremes and that little has been known of the majority of species falling somewhere in between. The species shown in Figure I are those for which some field data are available, and the intention is to suggest only the broad outlines of adaptation to life on the ground or in the trees.