Ravens possess an understanding of perception-goal psychology – a basic ‘Theory of Mind.’
Photo: Dianne Villota
There they are, these storied jet-black birds with their thick beaks, forbidding miens and ominous calls of “kraa, kraa, kraa,” hopping on the ground or perching in branches in many a park.
Common ravens (Corvus corax) are, well, common, and many of us barely pay them any mind. Perhaps we should, though. Ravens possess a surprisingly sophisticated mind of their own.
Biologists have long known that corvids (a family of passerine birds that include crows, ravens, jackdaws and magpies) are among the smartest feathered creatures on Earth. Some of them, like New Caledonian crows, have been known to create compound tools for fishing out food from tight spots with admirable alacrity.
Recently scientists confirmed something even more amazing: ravens are intelligent animals that even have the capacity for abstract thought – of the kind that was previously assumed to be possessed only by humans and possibly chimpanzees.
Researchers at the University of Vienna, in Austria, devised a clever set of hide-and-seek experiments for 10 captive ravens and observed them over a six-month period. The scientists placed pairs of the famously intelligent birds in adjacent rooms separated by a window so the two ravens could watch each other hide treats that they were given. Then, they covered the window but left a peephole in it and taught the animals how to spy on each other through it.
Here’s the shocking discovery: When the peephole was open, the birds took great care to hide their treats, but when it was closed, they didn’t – even though they could still hear that another bird was present in the adjoining room. That is to say, even when they could not see another bird, the ravens knew they might be being spied upon through the peephole, just as they could themselves spy upon others through it.
Ravens, which are highly social animals that often show empathy to one another and can be positively conniving, “possess an understanding of perception-goal psychology – a basic ‘Theory of Mind,’” the authors explain in their paper. In other words, a raven can infer what another animal might be thinking. “This shows that traits that we consider ‘uniquely human’ may be found in animals too,” said the study’s lead author Thomas Bugnyar, a professor at the University of Vienna and a leading expert on animal cognition.
Think about that: these relatively small commonplace birds are right up their with chimpanzees and dolphins as the smartest members of the animal kingdom. They are also environmentally conscious (kinda), or at least can be trained to be so. Crows living in a park in rural France have been trained to collect litter, like discarded cigarette butts.
“The park is very clean,” the park’s president Nicolas de Villiers was quoted as saying. “The purpose of the crows … is to educate the people, to open their minds, to think, ‘OK, the birds are able to do something that we are much more able to do than them, so we should do this by ourselves.’”