Preliminary investigations of ultraviolet-induced markings on domestic turkey chicks and a possible role in injurious pecking

1. Several gallinaceous species including domestic turkeys have the capacit y for ultraviolet (UV) vision. This might function in signalling between bi rds, for example in individual recognition, which would suggest the presenc e of plumage markings visible under UV radiation. 2. Between 1 and 22 d of age, the plumage of 17 male turkey poults (BIG6) w as examined. When viewed under a conventional fluorescent white luminaire ( which emits minimal UV) the birds were a uniform yellow or white according to the stage of feather emergence. However, when viewed under a lamp emitti ng radiation with peaks in the UV spectrum, distinct fluorescent and non-fl uorescent patches were observable on several parts of the body including th e wings, tail, shoulders, thighs, neck, breast and dorsal surface. 3. This paper describes the changes in incidence, size, location and qualit ative aspects of these UV-visible markings. 4. The age at which UV-visible markings were first observed on the wings an d tail corresponded closely with the age at which injuries to these sites w ere first caused by pecking as reported previously. It is suggested that th e 'unnatural' appearance of these markings under conventional lighting, whi ch emits minimal UV radiation, might attract or protract injurious pecking from conspecifics.