According to researchers who believe that listening to the birds can help breeders improve the welfare of their flocks, people can tell if chickens are chirping or frustrated from their calls.
Scientists played audio recordings of hens to nearly 200 volunteers and found that 69% could tell the difference between birds that were happy about an impending treat and those that were annoyed that no such reward was forthcoming.
Joerg Henning, a professor of veterinary epidemiology at the University of Queensland and senior author of the study, said: “People involved in chicken farming can identify the emotional state of the birds they are looking at, even if they have no previous experience.”
The work points to an apparent common ground that many animals share in how they express their feelings. More practically, it paves the way for acoustic monitoring of chickens that uses artificial intelligence to measure the mood in the coop and alert breeders when their hens are not happy.
If such monitoring proves reliable, Henning said, it would provide “a convenient and cost-effective way to improve welfare assessment methods in the commercial chicken production industry”.
The Victorian naturalist Charles Darwin suspected that animals further down the tree of life expressed their emotions vocally. Write in The descent of man in 1871 he described how the ability could have developed through successive adaptations in the animals’ vocal organs. This raised the prospect that many creatures not only shared a predisposition for emotion-laden calls, but that they could also respond to emotions in other species’ calls.
To see if people could identify emotions in chicken calls, Henning and his colleagues played voluntary audio recordings of hens. The birds were trained to associate different sounds, such as beeps, rings and buzzes, with the contents of a bowl hidden behind a swinging door. The surprises ranged from mealworms and regular chicken feed to dust to clean their feathers and a rather disappointing empty bowl.
When the chickens knew there was a treat behind the door, they produced a barrage of rapid claws or high-pitched staccato claws known as food calls, but when there was nothing to get excited about, they responded with whines and long, wavering wails known as gackling calls.
Each volunteer heard 16 recordings, all of the same length. Half were from chickens preparing for a treat, and half from birds that knew no such treat was coming. While almost 70% of the volunteers, recruited from the researchers’ professional networks and advertisements in online poultry journals, could distinguish the excited chickens from the frustrated ones, older people were less accurate, perhaps because they had poorer hearing. The work is published in Royal Society Open Science.
The findings build on recent research suggesting that people around the world can interpret emotions in the calls of a wide variety of animals, from tree frogs and alligators to crows and giant pandas. The results led scientists to suspect that terrestrial vertebrates share an emotional vocal signaling system, consistent with Darwin’s thinking.
If the idea survives further investigation, monitoring chicken calls could be written into animal welfare assessments, Henning said, which would be especially valuable on farms that keep thousands of birds. But small farmers can also benefit from knowing that their perception of chicken calls has a good chance of being correct, he added.
