As we know, crows are very intelligent. According to new research being published this week, 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. John Marzluff, University of Washington professor of environmental and forest sciences, is the lead author of a paper on this being published the week of Sept. 10 in the online edition of the Proceedings of the National Academy of Sciences.

Previous research on the neural circuitry of animal behavior has been conducted using well-studied, often domesticated, species like rats, chickens, zebra finches, pigeons and rhesus macaques. This time the study involved wild animals, specifically 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.

For the four weeks they were held 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. Rather than starting off by sedating the crows as is the normal standard procedure to study brain activity, a bew approach was used instead. This approach was developed by the UW and 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. After the work was completed all the birds were returned to the wild.

"The regions of the crow brain that work together are not unlike those that work together in mammals, including humans," according to John Marzluff. "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. The amygdala is the region of the vertebrate brain where negative associations 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 vertebrates as well. This new approach enables researchers to study the visual system of birds and how the brain integrates visual sensation into behavioral action."

Marzluff has suggested that the findings might also offer a way to reduce conflict between birds and endangered species on which they might be feeding as is the case in the Mojave Desert, where ravens prey on endangered desert tortoises or where crows and ravens prey on threatened snowy plovers on the east and western coasts.

"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 birds to avoid that area or that particular prey by catching them as they attempt to prey on the rare species."