Crocodilians — crocodiles, alligators, gharials, and caimans — are among the most ancient and misunderstood reptiles in zoo collections. Meeting their complex environmental, thermal, and behavioural needs requires specialist knowledge and purpose-built facilities.
Crocodilian welfare in zoos is most commonly compromised by inadequate thermal gradients and poor water quality. Without access to both warm basking sites and deep cool water, crocodilians cannot properly regulate their body temperature, impairing digestion, immune function, and metabolic health. Behavioural impoverishment is significant in many older facilities where featureless concrete pools offer little opportunity for natural substrate exploration, basking hierarchy negotiation, or aquatic hunting behaviour. Enrichment for crocodilians is less studied than for mammals but includes food-based enrichment, varied substrates, and occasional live prey items for appropriately sized species. Transport of large crocodilians for collection management involves significant capture stress and requires careful sedation and monitoring protocols. Welfare outcome measures for crocodilians are less developed than for other taxa, representing a gap in zoo welfare science.