Macaque species, specifically rhesus (Macaca mulatta), are the most common nonhuman primates (NHPs) used in biomedical research due to their suitability as a model of high priority diseases (e.g., HIV, obesity, cognitive aging), cost effective breeding and housing compared to most other NHPs, and close evolutionary relationship to humans. With this close evolutionary relationship, however, is a shared adaptation for a socially stimulating environment, without which both their welfare and suitability as a research model are compromised.
The provision of adequate space for laboratory animals is essential not only for good welfare but accurate studies. For example, housing conditions for primates used in biomedical research may negatively affect welfare and thus the reliability of findings. In common marmosets (Callithrix jacchus), an appropriate cage size enables a socially harmonious family environment and optimizes reproductive potential. In this study, we investigated the effects of cage size on body weight (BW), behavior, and nursing succession in the common marmoset.
With very few counterexamples (Andrews & Rosenblum, 1994; Fagot, Drea, & Wallen, 1991), researchers interested in primate nonsocial cognition have favored the test of isolated animals (for a review, see Drea, 2006). In these studies, the primates have traditionally been caught for their daily testing in an experimental area spatially separated from their living quarters. This classical procedure (CP) has demonstrated its efficiency. Most of what is currently known on primate cognition—for instance, regarding their perception, memory, reasoning, and conceptualization—has been collected in that way.