Engineering a rational approach to primate space requirements (1996)

Crockett, C. M., Yamashiro, J., DeMers, S. et al.

Abstract

The subjects spent significantly more time on the front half of the perch in the standard cage. ... On the basis of this observation, we highly recommend that solid-sided cages be placed in rooms such that the perches are installed on the cage side farthest from the room door, allowing the monkeys to view the door while seated on the perch.