Can Some Animals Adapt Better to Captivity than Others?

There are significant differences among species in their ability to adapt to captivity. Some species breed well in captivity and usually show no apparent signs of poor welfare, while other highly similar species sometimes live only a short time, breed little or not at all and often show abnormal behaviours. Marine mammals provide several examples of these differences. Thus, the life expectancy of bottlenose dolphins (Tursiops truncatus) in captivity is similar to that of their conspecifics in the wild, and the rate of reproduction of this species may be even higher in captivity than in the wild. By contrast, other species of toothed cetaceans such as Fraser’s dolphin (Lagenodelphis hosei) and Dall’s porpoise (Phocoenoides dalli) are extraordinarily difficult to keep in captivity. Among pinnipeds, walruses (Odobenus rosmarus) breed poorly and have a low life expectancy in captivity, and frequently show oral stereotypes. At the other extreme, gray seals (Halichoerus grypus) breed well in captivity and have a life expectancy equivalent to that of their counterparts in the wild. These differences among species are important because they allow us to anticipate problems and predict which animals are more susceptible to the potential negative effects of captivity. Moreover, understanding the mechanisms that explain these differences would be very useful in the design of strategies to improve the welfare of wild animals in captivity. Despite its importance, the study of differences in the ability of species to adapt to captivity is not exempt from methodological problems. If we use as a criterion of adaptation to captivity the average life expectancy, for example, we will have to take into account that the differences between two species could be due to a better ability of one species to adapt to captivity than the other species, or due to that one species has, in itself, a longer life expectancy than the other. This is reason why we have to express the average life expectancy of each species in captivity in relation to their life expectancy in natural conditions. A second methodological problem is that not all species show the same signs of poor welfare. Therefore, before concluding that a species adapts better than another, we must ensure that we have evaluated several indicators or we have chosen an indicator that is equally relevant to both species. Despite these difficulties, several studies have rigorously compared the adaptation to captivity of several species (see Table). The results of these studies as well as the observations of caregivers and veterinarians suggest the following considerations: www.zawec.org ZOO ANIMAL WELFARE FACT SHEET No 3 / FEBRUARY 2016