Crows: More like us than you think!

Crows have always been famous, even in the media: you have Maleficent’s favorite pet –and rather good-looking human servant in the most recent Disney adaptation–, the ones from Dumbo, or the three-eyed variety that keeps appearing in Bran Stark’s dreams… and countless others. Crows have always been pretty well-known for being clever and for always being around in suspenseful moments to caw threateningly in the distance. But besides the fact that they’re attracted to shiny objects –which, by the way, isn’t true– people don’t know much about them. And you’d be surprised at how similar to us they really are.

There are many different kinds of crows spread out all across the world, with the exception of Antarctica, and they’re particularly remarkable because they’re extremely comfortable living in urban areas: just like humans. Scientists speculate that they thrive in our cities because they like open areas, warmth, and having food easily available to them– well, we all do, really. It also helps that we’ve gotten rid of most of their predators (except for human ones armed with shotguns).

Crows have the amazing ability to recognize people. John Marzluff from the University of Washington recently conducted an experiment where he and a few other scientists put on masks and frightened some crows by catching them. Afterwards, whenever they did as much as take a leisurely walk in the area while wearing those masks, the crows would begin cawing aggressively and would even swoop down on them to try and scare them away. [Audio: recording of an angry crow caw] The surprising part is that the more they did it, the more the other crows picked up on the affected crows’ attitude towards the scientists and they began to show the same aggressive behavior towards them, until it was impossible for the scientists to come anywhere near the area with those masks on (this amazing power of recognition has led some people to theorize that we could get crows to work with our police force to identify criminals). [Picture: crows in police uniforms!]

In fact, the experiment went so far as to show that despite only having seen their parents react to the masks a couple of times, hatchling crows were able to remember the scientists’ masks two years later when they were adults, cawing aggressively in the same manner their parents had done even though they themselves had never come in contact with them. 

What this tells us is that crows are much more evolved than we initially thought. The fact that consecutive generations can build upon each other’s knowledge points clearly towards the beginnings of the development of a culture, something rarely seen in animals and only fully realized in human beings!

The communication between crows is all the more interesting given the fact that scientists have been able to identify over two hundred and fifty distinct crow calls. Each crow has an individual voice and speaks at least two dialects: one characterized by loud caws, used with the general crow community, and another one made of quieter calls, which used only among close family members. Even their warning calls can be classified into “cat!”, “hawk!” and “human!”

It has been proven in many places that if a crow is killed there, it can take as much as two years for any crow to fly over that area again; flocks will even change their entire migration pattern. And in some cases like in Chatham, Canada –one of the biggest crow roosting sites in the world–, crows have learned the exact distance a shot can travel, and can now fly just out of reach from their attackers. 

And just in case you’re still not convinced that crows are awesomely clever: crows actively work to deceive each other. They’re experts at hiding food, and sometimes even pretend to find food in places where there really isn’t any, using those places as decoys while they sneak off to find the real stash on their own!

Crows are also really good at using tools. They’re among the few species of animals that actually employ tools to find food (and not just food; if you look it up you’ll find a video of a crow snowboarding on a snowy roof in Russia using a bottle cap). They’ve been known to drop nuts on asphalt roads, calculating the weight of the nut and the exact distance they need to drop it from. They’ve even learned to have cars crack the nuts for them, and to wait at intersections for the light to turn red before they swoop down to get their food, lowering the risk of getting run over! [Picture: crows waiting at stoplights]

Still not enough to convince you of how intelligent crows are? Scientists set up a kind of obstacle course to see how far they could use their skills to get food. New Caledonian crows [Picture: New Caledonian crows, possibly a map showing New Caledonia] proved that they could fly to a branch to pull up a string that had a stick tied to it, untie the stick, carry the stick down to a box, use the stick to pull out a larger stick and then use that larger stick to finally pull their food out! The only other animals capable of going through so many steps without getting confused are primates.

And here’s something that’s just astounding: crows can make their own tools! We used to believe that only humans could do this; now we know that some animals can do it too. But not even chimpanzees, which we consider our closest genetic relatives, have been known to use hooks. And New Caledonian crows have made hooks of their own to get food.

So why are crows so smart?

There haven’t been that many studies about them yet, but so far we’ve been able to guess at some of the reasons for their startling intelligence. Firstly, their brain size in relation to their bodies is about the same as it is with primates. [Picture: parts of a crow's anatomy] Secondly, we may be partly responsible for this intelligent evolution: by living in such close proximity to us, crows have adopted an extremely diverse diet (you would, too, if you ate out of trashcans all the time) which forces them to discover different ways to eat meals that their bird-ancestors couldn’t dream of– like canned corn, mashed potatoes and gummy bears. [Picture: crows eating gummy bears!]

Alex Kacelnik, a zoologist from Oxford University, states that there are three elements to animal learning: what they inherit from their parents, what they learn from individual experience, and what they acquire through social input. When looking at crows and the way they interact with their surroundings, it’s obvious that they’re extremely developed in all three aspects. Besides crows, only primates have been able to show the same prowess in using and making tools, or have ever been known to pass information down to their young in a way that’s extremely similar to the way we educate our children.

So next time you see a crow remember that besides the fact that he’s small, black and can fly, you aren’t as different as you may think.

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VIDEO OF A CROW SNOWBOARDING:
https://www.youtube.com/watch?v=3dWw9GLcOeA

AWESOME DOCUMENTARY ABOUT CROWS:
https://www.youtube.com/watch?v=3TiXCWGivDo

SOURCES:
http://www.pbs.org/wnet/nature/episodes/a-murder-of-crows/crow-facts/5965/
http://www.birds.cornell.edu/crows/crowinfo.htm
http://io9.com/5969515/corvids-the-birds-who-think-like-humans
http://news.nationalgeographic.com/news/2006/06/060606-crows_2.html