Managing Aged Animals in Zoos to Promote Positive Welfare: A Review and Future Directions

Simple Summary Many animals experience physical and behavioral changes as they age. Age-related changes in physical or mental ability can limit the opportunities for animals to experience positive well-being. As animals in zoos are living longer than ever, understanding common physical, cognitive, and behavioral changes associated with ageing across species can help inform management practices. This review aggregates information about common age-related changes across a wide number of species, discusses the potential welfare impacts of these changes for ageing animals, and suggests methods for caretakers to maximize positive welfare opportunities for ageing animals under human care. Improvements in veterinary care, nutrition, and husbandry of animals living in zoos have led to an increase in the longevity of these animals over the past 30 years. In this same time period, the focus of animal welfare science has shifted from concerns over mitigating negative welfare impacts to promoting positive welfare experiences for animals. For instance, providing opportunities for animals to exert agency, solve problems, or acquire rewards are all associated with positive welfare outcomes. Many common age-related changes result in limitations to opportunities for positive welfare experiences, either due to pain or other physical, cognitive, or behavioral limitations. This review aggregates information regarding common age-related physical and behavioral changes across species, discusses how age-related changes may limit positive welfare opportunities of aged animals in human care, and suggests potential management methods to help promote positive welfare for animals at all life stages in zoos and aquariums.