Feather Corticosterone Measurements of Greater Flamingos Living under Different Forms of Flight Restraint.
Animals 2020,10: 605-619. doi:10.3390/ani10040605. www.mdpi.com/journal/animalsArticle
Greater Flamingos are commonly kept under flight restraint in zoos. Some are pinioned, others only featherclippedand some remain physically intact butlive in aviariesthat areoften not large enough to fly. In this study, we compared these three groups by measuring corticosterone (a hormone associated with stress)in their feathersin order to find out which of the restraining methods is most compatible with animal welfare. Additionally, we carried out behavioralobservations on all groups to detect potential stressors other than the status of flight itself. We expected to find differences in CORTf between deflighted and airworthyflamingos. However, no significant differences in feather corticosterone were measured between the three groupsand the hypothesis was rejected. The most important factor for the level of corticosteronewas found to be the zoological institution itself, reflecting the housing conditions.We hypothesizethat the method by which a Greater Flamingo is hindered from flying does not have measurableeffect on the corticosterone concentration in its feathers.Although these findings suggest that all methods are equally impacting animal welfare,we highlight the need for further improved studies based on this model.