Motor activity of different-aged Cercopithecidae: silvered-leaf monkey (Presbytis cristatus Esch.), lion-tailed monkey (Macaca silenus L.), moor macaque (Macaca maura Cuv.) as observed in the Zoological Garden, Berlin (West).

The activity of different-aged monkeys belonging to three species of Cercopithecidae was quantitatively analyzed in a 1 1/2-year study. The species, silvered-leaf monkey (Presbytis cristatus Esch.), lion-tailed monkey (Macaca silenus L.) and moor macaque (Macaca maura Cuv.) were observed in the Zoological Garden, Berlin (West). The data of a combined cross-sectional analysis across all three species indicate that the course of age-related changes in the frequency of movement can be depicted as graduated and differentiated. These results are discussed in terms of a reverse development pattern in old age compared to that of early youth.