People can tell if chickens are chirpy or frustrated from their calls, according to researchers who believe that listening to the birds could help breeders improve the welfare of their flocks.
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 imminent treat and those that were annoyed that no such reward was forthcoming.
Joerg Henning, a professor in veterinary epidemiology at the University of Queensland and senior author on the study, said: “People involved in chicken husbandry can identify the emotional state of the birds they look after, even if they do not have prior 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 chicken flocks that uses artificial intelligence to gauge the mood in the coop and alerts breeders when their hens aren’t content.
If such monitoring proves reliable, Henning said, it would provide “a convenient and cost-effective way to enhance 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. Writing in The Descent of Man in 1871, he described how the ability might have evolved through successive adaptations in the animals’ vocal organs. It raised the prospect that many creatures not only shared a knack for emotion-laden calls, but that they might respond to emotions in other species’ calls too.
To see if people could identify emotions in chicken calls, Henning and his colleagues played volunteers audio recordings from hens. The birds had been trained to associate different sounds, such as beeps, rings and buzzes, with the contents of a bowl hidden behind a swing door. The surprises ranged from mealworms and normal chicken feed to dust for cleaning their feathers and a rather disappointing empty bowl.
When the chickens knew a treat lay behind the door, they produced a barrage of fast clucks or high-pitched staccato clucks known as food calls, but when there was nothing to get excited about, they responded with whines and long, wavering moans known as gakel calls.
Each volunteer heard 16 recordings, all of the same length. Half were from chickens that were preparing for a treat, and half from birds that knew no such treat was coming. While nearly 70% of the volunteers, recruited from the researchers’ professional networks and adverts in online poultry journals, could tell 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 that suggests humans around the world can interpret emotions in the calls of a vast range of animals from tree frogs and alligators to ravens and giant pandas. The results have led scientists to suspect that terrestrial vertebrates share an emotional vocal signalling system, in line with Darwin’s thinking.
If the idea survives further investigation, chicken call monitoring could be written into animal welfare assessments, said Henning, which would be particularly valuable on farms that hold thousands of birds. But smallholders could also benefit, he added, from knowing that their perception of chicken calls has a good chance of being correct.