Facial blushing and feather fluffing are indicators of emotions in domestic fowl (Gallus gallus domesticus)
The study offacial expressions inmammals provided great advances inthe identification of their emotions and then inthe comprehension oftheir sentience. So far, this area of research has excluded birds. With anaturalist approach, we analysed facial blushing and feather displays indomestic fowl. Hens were filmed insituations contrasting inemotional valence and arousal level: situations known toindicate calm states (positive valence /low arousal), have rewarding effects (positive valence /high arousal) orinduce fear-related behaviour (negative valence /high arousal). Head feather position as well as skin redness ofcomb, wattles, ear lobes and cheeks varied across these situations. Skin ofall four areas was less red insituations with low arousal compared tosituations with higher arousal. Furthermore, skin redness ofthe cheeks and ear lobes also varied depending on the valence of the situation: redness was higher insituations with negative valence compared tosituations with positive valence. Feather position also varied with the situations. Feather fluffing was mostly observed inpositively valenced situations, except when hens were eating. We conclude that hens have facial displays that reveal their emotions and that blushing isnot exclusive tohumans. This opens apromising way toexplore the emotional lives ofbirds, which is acritical step when trying toimprove poultry welfare.
