Pecking order: Female chickens have shown signs of anxiety when their young were in distress
You might think chickens are way down the pecking order in the animal kingdom when it comes to emotional intelligence.
But it turns out that mother hens are such attentive, caring parents that they ‘feel’ their chicks’ pain.
In experiments, female chickens showed clear signs of anxiety and upset when their young were in distress.
It's the first time that scientists have shown hints of empathy - the ability to feel someone's pain or see their point of view - in a bird.
The discovery doesn't just shed lights on bird brains, it has important implications for the welfare of chickens in battery farms and science laboratories.
Empathy was once thought to be a uniquely human trait.
However, recent studies suggest animals may also be able to feel another creature's suffering, or even see the world through another animal's eyes.
The British researchers chose hens and chicks for the study because empathy is assumed to have evolved to help parents look after their young.
Jo Edgar, a Phd student at Bristol University, who led the study, 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.
'Our research has addressed the fundamental question of whether birds have the capacity to show empathic responses.
'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 tested the mother hens' reactions when their chicks' feathers were ruffled with a puff of air.
When the chicks were exposed to air puffs, they showed signs of distress that were mirrored by their mothers.
The hens' heart rates increased, their eye temperature lowered - a recognised sign of stress - and they became increasingly alert.
Levels of preening were reduced and the mothers made more clucking noises towards the chicks.
The findings were reported online today in the journal Proceedings of the Royal Society B.
Under commercial conditions, chickens regularly encounter other birds showing signs of pain and distress 'owing to routine husbandry practices or because of the high prevalence of conditions such as bone fractures or leg disorders', said the researchers.
Past studies have shown that mice injected with a chemical that gives them mild stomach ache feel more discomfort if they can see cage mates suffering from the discomfort.
Other experiments have shown that great apes - such as chimps and gorillas, probably feel empathy, as do dolphins, elephants and dogs.