The Role of Environmental Enrichment in Shaping the Behaviour and Welfare of Humboldt Penguins (Spheniscus humboldti) Housed in Zoos

This narrative review discusses how environmental enrichment may support the expression of species-typical behaviour and contribute to the welfare of Humboldt penguins (Spheniscus humboldti) kept in zoos. The literature indicates that behavioural diversity, activity patterns, enclosure use, social interactions and health status should be considered together when evaluating welfare. In captive settings, opportunities to swim, explore and engage in food-searching behaviours may be influenced by enclosure design, substrate, feeding practices and visitor-related stimuli. Available studies suggest associations between activity, use of the aquatic environment and foot health, but not establish that any single enrichment intervention directly prevents pododermatitis. The article reviews social, occupational, nutritional, physical, sensory, and cognitive enrichment and presents examples of enrichment approaches that could be considered when managing a colony of approximately twenty penguins. These proposals are intended as examples of enrichment opportunities derived from the available literature and husbandry experience rather than as universally validated management recommendations, and their implementation should be adapted to individual animals and local institutional conditions. It also outlines a preliminary monitoring checklist intended to support routine observation, not to serve as validated welfare scale or diagnostic instrument. Enrichment options, including mirrors, bubbles, manipulate objects, water devices and alternative food presentation, should be introduced gradually and evaluated in relation to individual responses. Live prey, if considered, requires additional assessment of prey-animal welfare, biosecurity, legal requirements and possible visitor concerns. Enrichment should complement, rather than replace, suitable housing, space, group management, nutrition and veterinary care.