Ravens can read one another’s minds: researchers discover

Mere cache-hiding might be “one-to-one stimulus responses”, ravens’ individual trial and error when they see another bird looking their way. Buckner, together with Stephan A. Reber and Thomas Bugnyar, cognitive biologists at the University of Vienna, are the authors of the research study.

“Maintaining a stable relationship with another sophisticated agent over time, as humans know, can itself be challenging”, he says.

Buckner, whose research concentrates on animal cognition, said the researchers avoided that concern in this latest study by using only open peepholes and sounds to indicate that a competitor might be present or nearby, with the ravens never able to physically see another raven in the context of the experiment. They did not show the same concern when the peephole was closed, despite the auditory cues.

The ability to cache food is important to ravens, and previous research had shown they behave differently when they perceive a competitor watching.

However, the scientists found that as well as spying on each other, ravens use tricks to deceive other birds and throw them off track. this behavior suggests that they know they’re being watched, and they know other ravens want to steal their food. Or are they just reacting to physical stimuli: visible raven plus a fresh food cache equals lost supper? “It makes them a good place to look for social cognition, because similar social pressures might have driven the evolution of similarly advanced cognitive capacities in very different species”. A number of studies have found that animals are able to understand what others see – but only when they can see the head or eyes, which provide gaze cues. After a group comes across some carrion, and has eaten as much as they can, birds will tuck remaining bits into their throat pouches, then scoot off to bury the scraps in hidden caches they can come back to later.

Researchers selected raven as a subject for studying “Theory of Mind”- the ability to attribute mental states including intents, desires, knowledge and vision. The birds were placed in adjoining rooms divided by a window that was initially left uncovered so one raven could watch while the other was given food to hide. The raven making the cache knows it is probably being observed through the spy hole and acts accordingly.

Martin Schmelz at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, says the study refutes a major argument against previous studies and shows exciting social cognitive abilities in ravens for the first time. The subjects (ravens) still cached as though they were being observed.

“Consequently, we argue that they represent “seeing” in a way that can not be reduced to the tracking of gaze cues”, they said. “It could change our perception of human uniqueness, that we share some of that ability not just with chimpanzees and closely related species but also with a very different species”, he said. This suggests that these animals are responding only to surface cues, and are not experiencing the same abstraction as humans.

According to Cameron Buckner, finding that the Theory of Mind is present in birds would require humans to give up the belief that we are special because of our “unique” mental capabilities. Some say Theory of Mind helped develop language: you point and say chien, I say dog, but we can both figure out what we mean.