Perching is a fundamental overnight roosting behaviour in chickens that protects against predators in nature and whose denial in cage systems represents a significant welfare compromise.
Perching welfare is both physical and psychological: physically, roosting at height exercises the keel bone and develops musculature; psychologically, the ability to roost satisfies a strong instinctive drive that persists across all chicken breeds. Hens in systems without perches show persistent motivation to seek height even on cage wires or equipment edges. The welfare case for perch provision is well-supported by both behavioural motivation research and bone health evidence.