Influence of availability of perches on the behavioral well-being of captive, group-living mangabeys (1996)

Neveu, H., Deputte, B. L.

Abstract

A total deprivation of perches yielded an increase in aggressive behaviors and locomotion, and a decrease in cohesiveness. Placing perches progressively in the experimental cage restored the level of all the variables to levels found in the control cage [with five perches]. ... Therefore, perches constitute a necessary feature of an adequate environment for mangabeys.