Wild animals in zoos: A new paradigm is needed for zoos in the future

This review describes the main approaches used for working with wild animals in zoos, and briefly traces the history and theoretical background of these approaches. The theoretical background should be considered when current approaches are discussed for the improvement and design of future zoos. Hediger’s individual-based concept of 'Zoo biology' is introduced, followed by a (small) population-oriented approach. Further approaches are presented focusing on animal welfare and behavioural/environmental enrichment concepts. We found that for all approaches, there is a lack of consideration of concepts of evolutionary theory. Lacking these concepts and the divergent backgrounds of the approaches might `account for the management and resulting sustainability problems. Recent management concepts that are based on evolutionary theory, particularly life-history theory, are proposed. The use of these concepts requires a change in paradigm in terms of focusing management and husbandry on the individual phenotypes (the units of natural selection) that constitute a population, instead of focusing on populations as assemblies of genotypes. It is proposed that a paradigm change can support the development of a comprehensive and integrated management approach that would be more compatible with all critical aspects of the biology of the animals and treat them on the same level of importance. Since reproduction is central to evolutionary theory, the new paradigm would particularly emphasise the management of the reproductive biology of the species, and thus support breeding.