The Evolution of Zoos as Conservation Institutions: A Summary of the Transition from Menageries to Zoological Gardens and Parallel Improvement of Mammalian Welfare Management

Zoological institutions, which were once exclusively for entertainment, are now leaders of wildlife conservation. This centuries-long transition was punctuated by key milestones that reformed wild animal exploitation into a mission of protection. Modern zoos perform ex situ activities to preserve natural resources, which are enabled by the housing of wild species. Zoo-managed animals facilitate new scientific knowledge, public education, and strategic breeding to maintain genetic diversity. Prioritizing animal welfare management is a key advancement for modern zoos, as it lessens stress and improves quality of life. Environments enriched with sensory stimuli promote naturalistic behaviors and provide opportunities for instinctual activities like foraging and hunting. This increases resiliency by reducing stress and boredom. However, such approaches only benefit welfare when appropriately matched to the animal. Behavioral responses to environmental cues reflect how animals experience their environment, and properly documenting them informs management decisions. Other modern advancements include enclosure designs, research initiatives, public education programs, species-specific staff training, and collaborative population management among zoos. This review chronicles the milestones that shaped the role of modern zoological institutions in species and habitat preservation. It also discusses opportunities for the continued evolution of welfare management practices, which is fundamental information for zoo employees and stakeholders.