Captive wild animal nutrition: a historical perspective

Proper feeding management of wild animals in captivity incorporates both husbandry skills and applied nutritional sciences. As a basic foundation of animal management, nutrition is integral to longevity, disease prevention, growth and reproduction, yet has received insufficient focus in the zoological community, although somewhat more detailed attention has been paid to free-ranging wildlife, particularly those of economic value to man. The field of nutrition is itself a rather recent scientific discipline. In the nineteenth century the importance of major food constituents such as protein, fat, carbohydrate, and fibre was recognized, and mineral nutrition was receiving much attention. But not until this century has the essentiality of vitamins, fatty acids, amino acids, and many trace elements been demonstrated, with biochemical and molecular characterization of interactions among nutrients still relatively unexplored. Thus, it is not surprising that comparative animal nutrition, focused on zoo and wildlife species, has a relatively short, yet extremely productive and rewarding, history. Noteworthy and rapid developments in animal nutrition are demonstrated by the fact that twenty revisions of Feeds and Feeding, a widely used textbook, were published within the 50-year span following its initial printing in 1898 (Morrison, 1953). Discussions in the earliest editions, of necessity, were based largely on the experience and observations of successful farmers rather than the results of actual experiments. Thus, in the field of wildlife nutrition, qualitative, rather than quantitative, information provided the underlying basis for the development of diets fed to many wildlife species, and studies of food habits have continued as a major percentage of all wildlife nutrition investigations (Robbins, 1993). While detailed natural history documentation of field biologists supplies a written record of foods consumed by many species, such information with no chemical evaluation of dietary constituents, or assessment of utilization, provides only a partial basis for applied feeding programmes. Dietary choices of free-ranging wildlife are complex chemically, temporally, and spatially, and animals use a wide variety of morphological, physiological, and anatomical adaptations to acquire and utilize foodstuffs. Although we can rarely duplicate ingredients of any animal’s diet in a captive feeding situation, what we can duplicate, and must focus on, are the nutrients contained within those diets. Wildlife and zoo nutrition are integrally linked; physiological and biochemical components must be considered as critical as ecological and behavioural considerations in meeting the needs of the species under our care.