The program is not functioning correctly
The program is not working properly. This SciShow video is brought to you by Fetch. Fetch is a free app for earning rewards on anything you buy. Download the app and use the code SciShow to get 5,000 points when you scan your first receipt.
Humans like to think of ourselves as special. We point to how smart we are, how many wrinkles our brains have, and our unique brain regions to show just how different we are from animals. And other animals’ brains? That’s totally an insult. Calling someone a “bird brain” is the height of wit, probably, but it’s long past time to retire that one. Because studying bird brains isn’t just showing us how smart birds can be; it’s challenging old ideas of how smartness evolves in the first place, as well as just how unique humans really are.
Various human cultures have observed the smartness of corvids—birds like crows, ravens, and jays—for a long time. It’s just taken science a little bit to catch up. It’s hard to test the intelligence of animals that can’t communicate with humans, so we have to interpret their behavior to get a sense of what’s going on in there. One of those is tool use. Scientists define tool use in terms of using an external object to physically interact with something and change it in some way, or get information about the environment. So things like using a leaf to get ants out of a hole in a log, or using a stick to scratch an itch.
With that definition, tool use isn’t something all animals do, but it’s not totally uncommon. There have been reports of birds doing this kind of thing since at least the 1930s, but some birds, much like primates, take it one step further. They don’t just use tools; they manufacture and combine tools.
In a study published in 2002, researchers in the UK watched a New Caledonian Crow make her own tool to lift a bucket. The crows in the study had been choosing between a hooked wire and a straight wire to pick up a bucket of food, but when one of the other birds stole the hooked wire, rude, this little genius took the straight wire and bent it into a hook. She made her own, more efficient tool.
And in a 2018 paper, researchers put food in a box and taught crows that they could use a dowel to push food out. Then they took away the dowel and gave them objects that were too short to reach the food on their own, but put them together and you could achieve the same effect—and half the birds figured that out. The researchers figure making tools like that may require higher cognitive abilities, like planning and task coordination. In fact, most modern humans don’t start to show tool innovation skills until they’re between ages five and nine.
Most impressive of all, crows may even exhibit consciousness. Consciousness, in this sense, means not just experiencing something, but being aware that you’re experiencing it—something that, historically, we’ve only thought humans and a few other mammals can do.
In a 2020 paper, researchers in Germany showed two carrion crows a bunch of shapes. Sometimes the shapes were bright and easy to see; sometimes they were dimmer and right at the edge of what the crow could see; and other times, nothing was visible at all. The crows were trained to give a couple responses: sometimes they would say “Yes, I can see the thing,” while other times they were supposed to respond when they could not see it.
But the real key was what was happening in the crow’s brains. The term “neural correlates of consciousness” refers to the neuron activity required for a conscious experience—and only that specific conscious experience. Scientists study the neural correlates of consciousness by looking for brain activity that’s different when someone reports being aware of some stimulus versus when they don’t.
Now, here’s the key to this research: when you get right at the edge of what brightness you’re capable of seeing, sometimes you’ll see the shape and sometimes you won’t. So the researchers weren’t so much looking for whether the crow’s brain saw the shape; they were looking for whether the crow was going to say if they saw it. Certain neurons in the crow’s brains had