Reptiles are the most taxonomically diverse group in zoo collections, ranging from small geckos to Komodo dragons and large pythons. Their welfare needs as ectotherms — animals that regulate temperature from external sources — are distinct and often poorly understood.
Reptile welfare in zoo collections is often compromised by underestimation of their biological complexity. The fundamental requirement for a precise thermal gradient — not merely warm conditions, but a range of temperatures allowing behavioural thermoregulation — is frequently provided inadequately. Reptiles denied appropriate temperature gradients cannot mount immune responses to infections, process food normally, or maintain activity levels. UV-B provision for diurnal species is essential and must be of appropriate wavelength and intensity. Behavioural welfare for large species including monitor lizards and large constrictors requires substantial space and environmental complexity. The cognitive and emotional lives of reptiles are genuinely uncertain but warrant precautionary consideration given growing evidence of their complexity.