Crows react to threats in human-like way: Neural basis of crows' knack for face recognition

Sep 10, 2012 by Sandra Hines
Crows were captured by investigators wearing threatening masks. Although never treated in a threatening way, the crows associated negative feelings with the mask. Credit: Jack DeLap/U of Washington

(Phys.org)—Cross a crow and it'll remember you for years. Crows and humans share the ability to recognize faces and associate them with negative, as well as positive, feelings. The way the brain activates during that process is something the two species also appear to share, according to new research being published this week.

"The regions of the crow brain that work together are not unlike those that work together in mammals, including humans," said John Marzluff, University of Washington professor of environmental and forest sciences. "These regions were suspected to work in birds but not documented until now.

"For example it appears that birds have a region of their brain that is analogous to the amygdala of mammals," he said. "The is the region of the where are stored as memories. Previous work primarily concerned its function in mammals while our work shows that a similar system is at work in birds. Our approach could be used in other animals – such as lizards and frogs – to see if the process is similar in those as well."

Marzluff is the lead author of a paper being published the week of Sept. 10 in the online edition of the .

Previous research on the of animal behavior has been conducted using well-studied, often domesticated, species like rats, chickens, , and rhesus – and not like the 12 adult male crows in this study.

The crows were captured by investigators all wearing masks that the researchers referred to as the threatening face. The crows were never treated in a threatening way, but the fact they'd been captured created a negative association with the mask they saw. Then for the four weeks they were in captivity, they were fed by people wearing a mask different from the first, this one called the caring face. The masks were based on actual people's faces and both bore neutral expressions so the associations made by the crows was based on their treatment.

Investigators wearing caring masks fed the crows for four weeks. Credit: Jack DeLap/U of Washington

In most previous neurological studies of animals, the work usually starts by sedating the animals, Marzluff said. Instead the approach developed by the UW involved injecting a glucose fluid commonly used in brain imaging into the bodies of fully alert crows that then went back to moving freely about their cages. The fluid flooded to the parts of the crow brains that were most active as they were exposed for about 15 minutes to someone wearing either the threatening or caring mask.

Then the birds were sedated and scans made of their brains. All the birds were returned to the wild once all the work was completed.

Before brain scanning, a crow was exposed on and off for about 15 minutes to a person wearing either a caring mask or a threatening mask, but not both. Credit: Jack DeLap/U of Washington

"Our approach has wide applicability and potential to improve our understanding of the neural basis for animal behavior," wrote Marzluff and co-authors Donna Cross, Robert Miyaoka and Satoshi Minoshima, all faculty members with the UW's radiology department. The department funded the preliminary work while the main project was conducted using money from theUW's Royalty Research Fund.

Most neurological studies to date in birds have concerned their songs – how their brain registers what they hear, how they learn and come up with songs of their own. This new approach enables researchers to study the visual system of birds and how the brain integrates visual sensation into behavioral action, Marzluff said.

Ila Palmquist, a member of John Marzluff’s laboratory group, wears a threatening mask while catching and handling crows. The mask carries a neutral expression so the associations made by the crows was based on their treatment. Credit: Marzluff Lab/U of Washington

Among other things the findings have implications for lowering the stress of captive animals, he said.

"By feeding and caring for birds in captivity their brain activity suggests that the birds view their keepers as valued social partners, rather than animals that must be feared. So, to keep animals happy we need to treat them well and do so consistently," he said.

Intriguingly, Marzluff said the findings might also offer a way to reduce conflict between birds and endangered species on which they might be feeding. In the Mojave Desert, for instance, ravens prey on endangered desert tortoises. And on the West and East coasts, crows and ravens prey on threatened snowy plovers.

"Our studies suggest that we can train these birds to do the right thing," Marzluff said. "By paring a negative experience with eating a tortoise or a plover, the brain of the birds quickly learns the association. To reduce predation in a specific area we could train to avoid that area or that particular prey by catching them as they attempt to prey on the rare species."

The partnering of neuroscientists with ecologists could be used to better understand the neural basis of cognition in widely diverse animals, said co-author Cross. For example, her suggestion to use the glucose technique prior to brain scans, so the crows could be fully awake, could be used for other animals.

"This was a true collaboration that would never be possible without the people that were involved with very different areas of expertise," she said.

Explore further: Conservation and immunology of wild seabirds: Vaccinating two birds with one shot

More information: Brain imaging reveals neuronal circuitry underlying the crow's perception of human faces, PNAS, Published online before print September 10, 2012, doi: 10.1073/pnas.1206109109

add to favorites email to friend print save as pdf

Related Stories

Not so bird-brained: Clever crows recognise faces

Jun 29, 2011

Humans who dismiss birds as featherweights may revise their opinion when learning of crows which not only can identify the face of someone who is a danger but also teach others about the threat.

Crows found able to distinguish between human voices

May 16, 2012

(Phys.org) -- Researchers at the University of Vienna have discovered that carrion crows are able to distinguish between familiar and unknown human voices. They also found, as they write in their paper published ...

Crows are capable of distinguishing symbols, study finds

Oct 10, 2011

(PhysOrg.com) -- A new study published in Animal Behavior shows that crows are capable of recognizing symbols designed to represent different quantities and is one of many different studies currently lookin ...

Recommended for you

Nature offers video of 10 cutest animals of 2014

4 hours ago

(Phys.org)—The journal Nature has released a video that ventures a bit from its traditional strictly-science approach to technical journalism—it's all about the cutest animal stories of the past year ( ...

Big data and the science of the Christmas tree

8 hours ago

Often called the "Cadillac of Christmas trees," the Fraser Fir has everything a good Christmas tree should have: an even triangular shape, a sweet piney fragrance, and soft needles that (mostly) stay attached ...

User comments : 7

Adjust slider to filter visible comments by rank

Display comments: newest first

defactoseven
5 / 5 (1) Sep 10, 2012
It all goes to prove that scarecrows do not work. I think this is the point of this study.

I'm just being facetious. Crows are unusually intelligent creatures.
Telekinetic
2.6 / 5 (5) Sep 10, 2012

I'm just being facetious. Crows are unusually intelligent creatures.

Their cousins, African Grey Parrots' intelligence has been compared to a seven year old child's. I'm glad to hear that the researcher said, "So, to keep captive animals happy we need to treat them well and do so consistently." There are young activists in prison today with sentences reserved for a terrorist because they acted on the knowledge that animals held captive in labs were NOT being treated well. Animals live in a new era of the Spanish Inquisition in research labs all over the world. Dogs and chimps are routinely tortured for the "advancement" of medical science. Humans are inhumane.
Midcliff
3.3 / 5 (3) Sep 11, 2012
If your "activists" terrorized people then they ARE "terrorists" and belong in prison. There are civil ways to voice your opinions, like in posts and peaceful demonstrations and lawsuits.

besides that, all research with animals is required to be humane and the law is specific as to the definition of humane. If you see abuse, report it. If you don't like the accepted definition of humane, become a lawyer and change it.
alfie_null
3 / 5 (1) Sep 11, 2012
They seem more capable of recognizing differences in human faces than I think I would be able with crow faces. Then, I've never been held captive and fed by crows.
dankgus
5 / 5 (1) Sep 11, 2012
Um, why did they bother using masks? The experiment does not show that crows recognize faces, it only shows that they recognize different creepy masks.

--Dan
Telekinetic
2 / 5 (4) Sep 11, 2012
If your "activists" terrorized people then they ARE "terrorists" and belong in prison. There are civil ways to voice your opinions, like in posts and peaceful demonstrations and lawsuits.

besides that, all research with animals is required to be humane and the law is specific as to the definition of humane. If you see abuse, report it. If you don't like the accepted definition of humane, become a lawyer and change it.

Do you really think that medical labs comply with the law about humane treatment? The activists I refer to have been jailed on conspiracy charges when planning to release animals from cages in medical research labs, not terrorizing people. Do you know that a product of this type of research is Vioxx, which has been responsible for close to 100,000 deaths of people after it was prescribed by their doctors? Who are the terrorists?
Midcliff
1 / 5 (1) Sep 12, 2012
@TK You are contradicting yourself. If we didn't allow animal testing, then humans would be the guinea pigs and vastly more people would die on first trial. The animal testing is necessary to reduce risk to humans. I assume you value human life over animal life. (If not you would be unrealistic and not worth talking to.) Pharmaceuticals save far more lives than they harm. I agree the FDA should have been more agressive pulling VIOXX at first inkling of a problem. We need to strengthen laws and penalties there. But stopping animal testing would make drugs less safe, not more safe.

Also, you would be hypocritical unless you never drive or never use any products whatsoever(like a computer for typing your comments). Thousands of animals are inhumanely killed every year by vehicles used to deliver and manufacture the products you demand.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.