ABSTRACT
The domestic hen is of special interest to animal behaviourists because commercial poultry systems have been intensified so rapidly to meet economic pressures. As a result, the hen has attracted more welfare concern than any other farm animal. A hen is wary and shy, of limited ability and flexibility although it has good powers of visual discrimination. It developed in a bamboo forest habitat and its behaviour fits it for that niche. Though reluctant to fly, it uses both ground space for eating, dust bathing and nesting, and vertical space for roosting and crowing during its daily cycle of activity. The modern hen has developed from the jungle fowl which through domestication and early selection developed such traits as leanness, aggression, activity, pecking, leg slashing, social responsiveness and particular colours. Chick embryos respond to light as early as 17 days after the start of incubation.
