Hand rearing of captive chimpanzees: past, present and future, towards limiting this practice to promote animal welfare and conservation

Abstract

With this article, we aim to promote discussion about hand-rearing, in general and in the use of captive chimpanzees in the entertainment business, informed by evidence accumulated over recent decades. A vast amount of evidence suggests that maternal separation and hand-rearing have serious negative consequences on the physical, mental and behavioral development of non-human animals. Although there are common features to such effects across species, those with a comparatively long period of infancy and strong mother-infant bonds are relatively more susceptible to deleterious effects. This is because such species rely heavily on post-natal learning for the acquisition of crucial behaviors. Chimpanzees are one such species and studies show that chimpanzees separated from their mother early in life, are those most likely to: show impaired social behaviors; have difficulty raising infants appropriately; and to be unable to copulate (due to behavioral and not physical causes), the latter with conservation implications. Thus, from the perspective of animal welfare and conservation, unnecessary hand-rearing should be avoided and if absolutely unavoidable, infants should be reintegrated into social groups of conspecifics as soon as possible to minimize negative consequences. The number of cases of successful reintroduction of hand-rearing infants has increased recently, along with a decrease in the frequency of unnecessary hand-rearing, in zoos. However, the use of chimpanzees in entertainment shows continues to promote the unnecessary maternal separation and hand-rearing, in addition to deleterious effects involved in the training and exhibition of chimpanzees performing various, mostly species-unnatural, behaviors, for show on the stage, on television programs and across other media. Such entertainment shows also pose problems for environmental education. We need to switch to more humane and naturalistic ways of presenting chimpanzees to the public to encourage conservation activities. Hand-rearing should be limited, ideally, to cases of maternal rejection or infant abuse. However, it is sometimes difficult to make such a decision. To stop unnecessary hand-rearing and promote species-appropriate captive care, we need to create a network among institutions housing chimpanzees in order to: accumulate and share knowledge, expertise and resources; promote discussion; create standards/guidelines; and collaborate in reintroduction.