Chickens might not be eggheads, but they're hardly bird-brained, according to a leading animal scientist.
"The very idea of chicken psychology is strange to most people," says Dr Lori Marino, "but… chickens are just as cognitively, emotionally and socially complex as most other birds and mammals."
Dr Marino is a senior scientist at The Someone Project, an animal rights and research group, and found fame as one of the experts interviewed in controversial documentary Blackfish.
Reviewing the latest research into chicken intelligence, she says it's clear they're not the bird-brains most people think they are.
"The scientific literature on chicken cognition and behaviour is relatively sparse in many areas, and dominated by… their 'management' as a food source. In other studies, their welfare is ultimately related to productivity.
"Far less numerous are studies of chickens on their own terms - as birds."
In fact, according to Dr Marino's research, chickens:
- have basic arithmetic abilities from as early as five days old
- demonstrate self-awareness and self-control
- can reason and make logical inferences, equivalent to that of a seven-year-old human child
- can judge time, and anticipate future events
- discriminate against other chickens they don't like
- show emotions such as fear, anxiety and empathy
- have a "large repertoire of different visual displays and at least 24 distinct vocalisations"
- have distinct personalities, just like humans.
In many respects, Dr Marino says chickens have similar cognitive abilities to primates - humans' closest relatives - and even develop 'Machiavellian' strategies to get what they want.
"Males will sometimes make a food call in the absence of any food," she says.
"This serves to attract females who, once near them, can be engaged and defended against other males. Of course, females develop counter-strategies and eventually stop responding to males who call too often in the absence of food.
"These kinds of social strategies - deception and counter-strategies - are strikingly similar to the same kinds of complex behaviours identified in mammals, including primates."
"A shift in how we ask questions about chicken psychology and behaviour will, undoubtedly, lead to even more accurate and richer data and a more authentic understanding of who they really are," says Dr Marino.
Her findings have been published this week in journal Animal Cognition.