Tag Archives: National Geographic

Ravens and Crows: Geniuses of the Bird World

In Yellowknife ravens have figured out that the streetlights turn on when it gets dark, so they wrap their wings around these light-sensitive lamps to get a little warmth.

We didn’t teach these members of the corvid family (crows, ravens, magpies, rooks and jackdaws) to do this or any of the other smart things they do. Apes and dolphins move over. Bonus: corvid population seems to be growing; climate change be damned.

old wood

An article in Scientific American Mind, “Crows Show Off their Social Skills” describes research by biologist Barbara Clucas of Humboldt State University on the urban savvy skills of ravens in Seattle. They exhibit different behaviours depending upon whether humans are looking at them or merely walking by, eyes averted; they fly away when watched, less quickly when ignored.

Even better, corvids can distinguish between good guys and bad guys. John Marzluff of the University of Washington and his colleagues ventured into Seattle parks wearing two kinds of masks; those wearing bad-guy masks trapped the birds, the good guys didn’t.  Five years later, the researchers returned wearing their masks.  The crows who had been around for the original experiment not only remembered which of the masked scientists had trapped them, mobbing and shrieking at them, but had passed this information on to others.

“It’s one thing to learn from one’s own experience and another to observe what’s happening to other individuals and infer it could happen to you,” explains John Marzluff.  (We know from teaching our own kids this stuff what a difficult learning experience it is, and some of us never get it.)

Bullrushes

“The similarity to human brain activity and the parallels in social intelligence in general are significant,” writes Harvey Black in the social skills article, “because they have evolved after our last common ancestor existed 300 million years ago.  That would make our species’ similarities a case of convergent evolution, when two vastly different organisms develop the same traits independently.”

Corvids are supremely good at caching food, remembering where they stored thousands of caches by memorizing their precise locations. This ability extends to recording where other birds have stored their caches, and engaging in surreptitious drops to mislead their rivals. (Considering we have a hard time remembering where we put our things, never mind those things we have deliberately hidden, corvids have it all over us.)

It gets better. Another Scientific American article, ‘Just How Smart are Ravens?” describes how researchers Bernd Heinrich and Thomas Bugnyar designed an experiment to prove that ravens, the largest of the corvids are logical, meaning that they can study a problem and then in a few minutes, execute it perfectly (as opposed to engaging in random trial and error such as jabbing randomly at a key board in the hopes that this will somehow perform the function we want.)

The scientists presented ravens with a problem for which there was no equivalent in the natural world: a piece of meat hanging from a string from a branch.

“To get this treat, the bird had to reach down from a perch and grasp the string in its beak, pull up the string, place the loop of string on the perch, step on this looped segment of string to prevent it from slipping down, then let go of the string and reach down again and repeat its actions until the morsel of food was within reach.” Mission accomplished flawlessly. Check out the National Geographic video, noted below, to see this in action.

Ravens are scavengers, stealing food from predators that can easily kill them. They have to understand their adversaries’ reaction times and capabilities.  Corvids learn this by engaging in risky play activity, for example, by nipping them from behind to see what they’ll do. They have to think on their feet, observe, draw conclusions and pass on this knowledge to their friends and family.

For more on these fabulous birds, check out these great websites.

For the National Geographic video, “Perching Birds: Ravens and Intelligence”

http://video.nationalgeographic.com/video/animals/birds-animals/perching-birds/raven_intelligence/

For “Crows Show Off their Social Skills in Scientific American

http://www.scientificamerican.com/article.cfm?id=crows-show-off-social-skills

For “How Smart are Ravens?” captured in ScienceBlogs and posted by “GrrlScientist” from a Scientific American article on the subject

http://scienceblogs.com/grrlscientist/2007/04/09/just-how-smart-are-ravens/