Stress is a pervasive welfare concern in zoo animals. Recognising its signs and implementing evidence-based management strategies is central to modern zoo animal welfare.
Stress in captive animals arises from multiple sources: inadequate space, inappropriate social grouping, environmental monotony, loss of control, and exposure to human activity. Chronic stress causes significant suffering and impairs the health and reproductive success needed for conservation breeding programs. Modern zoo welfare management uses non-invasive stress biomarker monitoring alongside behavioural indicators to assess welfare states. Management strategies that reduce stress include providing predictable routines, giving animals control over interactions with the public and keepers, creating off-display retreats, rotating enrichment, and managing visitor behaviour near sensitive enclosures. Training animals to voluntarily cooperate with veterinary procedures eliminates restraint as a stressor.