Passive joint mobility in patas monkeys (Erythrocebus patas): rehabilitation of caged animals after release into a free-ranging environment.

A previous study of passive joint mobility in patas monkeys (Erythrocebus patas) showed that laboratory-caged animals had significantly greater mobility in most joints than age/sex matched free-ranging monkeys. Passive joint mobility on 27 of the same animals was measured 6 months after the caged animals were released onto a 40-hectare island. The results show that within 6 months of becoming free-ranging, typical passive joint mobility is restored. Thus, although caging directly affects measurements of morphologically-determined features in patas monkeys, confinement itself does not necessarily prevent rehabilitation if the immature monkeys are released into a free-ranging environment.