LAUSR

&NA; Reflection and fluorescence properties of feathered and non‐feathered body regions of white‐ and bronze‐colored fattening turkeys of various ages were examined by ultraviolet (UV) photography. The examinations were carried out on 20 white‐feathered fattening turkeys (B.U.T. 6; 10 males, 10 females) and 20 bronze‐feathered fattening turkeys (Grelier 708; 10 males, 10 females) over a period of 21 weeks. The turkeys were photographed once a wk under long‐wave UV (UVA) radiation illumination (λ = 344‐407 nm) using a digital camera. A bandpass filter was used for UV reflectography to filter out the visible components of the used light source. A longpass filter was used for UV fluorescence photography to avoid blurring in the image due to chromatic aberration as a result of UV illumination. We found that natal down feathers of white‐feathered turkeys showed an intense yellowish‐green fluorescence under UVA light. UVA fluorescence also was shown by the natal downs of the slightly melanized plumage areas of bronze turkeys. Vaned feathers of white fattening turkeys reflected UVA radiation. Freshly molted feathers were optically distinguishable from the previous feather generation due to their more intense UVA reflection. In bronze turkeys, both the bright end seams of the dark pennaceous feathers and rectrices and the bright banding of primary and secondary remiges reflected UVA radiation. Intense UVA fluorescence was recognizable in day‐old chicks of both color variants on the scutellate scales of the legs and toes. In male turkeys of both color variants, UVA‐reflecting parts were recognizable with increasing age on the featherless head region. The UVA‐fluorescent and UVA‐reflective characteristics of the plumage of fattening turkeys were closely related to the plumage color, the feather type, the molting state, and the age of the birds. Further research is needed regarding the UVA‐reflecting properties of the turkey plumage and the effects of full‐spectrum illumination, including the UVA spectrum, on the behavior and health of fattening turkeys.