Chicken research advances understanding of animal emotion

New research published in Proceedings of the Royal Society B reveals for the first time that domestic hens appear to be affected emotionally when their chicks are distressed.  The research suggests that birds possess one of the important attributes underpinning empathy and is the first study to use both behavioural and physiological methods to measure these traits in birds.

Scientists based at the University of Bristol’s Animal Welfare and Behaviour research group exposed chicks to a puff of air – causing the chicks mild distress – while their mothers watched.  At the same time they monitored the adult hens’ physiological and behavioural response.  The hens reacted with increased alertness, decreased preening and increased vocalisations directed to their chicks, as well as experiencing an increased heart rate and lower eye temperature.

Some of these responses have previously been used as indicators of an emotional response in animals.  Jo Edgar, PhD student in the School of Veterinary Sciences, said: “The extent to which animals are affected by the distress of others is of high relevance to the welfare of farm and laboratory animals.  We found that adult female birds possess at least one of the essential underpinning attributes of ‘empathy’; the ability to be affected by, and share, the emotional state of another.”

The researchers used chickens as a model species because, under commercial conditions, chickens will regularly encounter other chickens showing signs of pain or distress due to routine husbandry practices or because of the high levels of conditions such as bone fractures or leg disorders.  Although the authors point out that further work is required to understand the nature of the chickens’ response in more detail, they suggest that “the study provides an important platform to investigate the possible empathetic responsiveness of chickens.”