PUB - Publikationen an der Universität Bielefeld

Keeping animals in captivity should always favour conditions that aim to improve their welfare withrespect to species-specific requirements. For laboratory animals, the majority of welfare issues havebeen explored in rodents thus far, whereas the effect of housing conditions on the well-being of avian labspecies has received relatively little attention. Here, we investigate the importance of access to a waterbath in captivity on the welfare of a drought-adapted passerine, the zebra finch (Taeniopygia guttata).Zebra finches can survive long periods of drought in the wild, which also includes a lack of surface waterfor bathing, but if water is available, they regularly take the opportunity to bathe in water. Water bathsrepresent an important comfort behaviour for zebra finches, especially because the birds do not take dustbaths. Here, we wanted to examine the role of water baths in relation to corticosterone concentrationsas an indicator of well-being in captive zebra finches. We sought to determine how important it is toprovide water baths to zebra finches in captivity. Therefore, we repeatedly quantified the basal plasmastress hormone levels, i.e., corticosterone (CORT), and the body weight of individuals over a three-monthperiod. During this time, control birds had permanent access to a water bath, while treatment birdsexperienced a 30-day period without the opportunity to bathe during the second month. We demonstratethat zebra finches lacking bathing opportunities show higher basal plasma CORT concentrations (GLM,p = 0.034) but do not differ in body weight in comparison to control birds (GLM, p = 0.31). Our resultsshow that even for birds that can tolerate long periods of drought in their natural habitat, access to awater bath is essential for their well-being and their welfare, and thus, water baths should be providedunder captive housing conditions. As chronically elevated stress hormone levels can have short-andlong-term detrimental effects, our findings have important implications for welfare considerations inthe management of one of the most used laboratory birds.