How smart are crows?
đˇď¸ TĂ o lao
In one of Aesopâs 2500-year-old fables, a crow is searching for water. It spies a pitcher and discovers liquid inside, but itâs beyond reach. Soon, the crow begin dropping pebbbles into the pitcher. One by one, they displace the water, and the crow quenches its thirst. Insterestingly, this fable turns out to be pretty accurate. In a 2014 experiment, scientists placed a food reward in a tube partially filled with water, and watched as crow after crow dropped stone after stone in, until the food was in break-snatching distance. This is just one of many fascinating displays of intelligence from corvids, the bold, brainy family of songbirds, that includes crows, ravens, jays, and magpies. To start, corvids are strategic when it comes to their food. They ransack trash bins and snatch bites from under other birdsâ beaks.
They also hoard and cache their food. A single Clarkâs nuckcracker, for instance, is thought to scatter some 30000 pine nuts across more than 2000 cache sites, which it can recover more than 9 months later. And in one experiment, srub jays given waxworms and peanuts cached and retrieved the perishable worms first and left the peanuts for later. It seems the jays not only recalled where they buried things, but also what they buried and when. Whatâs more, experiments show that when srub jays will bury when they know it wonât be available the next day, suggesting they plan for future events too. And corvid abilities extend beyond meal prepping. In one experiment, a masked person trapped and released a wild crow. When the masked person returned, crows dive-bombed them. If they wore a different mask, however, they were ignored, suggesting that corvids can distinguiseh between and remember different human facial characteristics.
Crows also tend to gather around the bodies of their dead companions and caw, a behavior sometimes likened to a funeral. And one study showed that crows were slower to return to an area where theyâd seen a dead companion, suggesting they associated it with risk. Corvids like New Calendonian crows also demonstrate an impressive proclivity for reasoning and tool use. Even in the wild, they fashion sticks into hook-shaped probes for food. Some Japanese crows have been observed placing nuts on the road, waiting nearby, then retrieving the rewards once passing cars have cracked them open. But corvids also do things that are harder to explain. They sometimes tote trinkets around, which might help them practice caching or serve as gifts to their partners. And theyâve been spotted repeatedly sledding down roofs on plastic lids. Play activities like this are relatively common in corvids, especially juveniles.
Corvids have a longer developmental period than other songbirds. And itâs thought that play encourages learning and lays a strong foundation for their intelligent behavior. Some researchers think cleverness is crucial to the highly social lives of corvids. They breed cooperatively, live and communicate in large dynamic groups, share food, and mob predators together. Some have lifelong partnerships, where they recognize their companions and track, respond to, and even predict each otherâs behaviors and desires. Scientists today consider corvids among the smartest animals, a big step from where consensus used to be. In the late 1800s, German scientists Ludwig Edinger compared primate and crow brains, and interpreted the crowâs brain constructor as primitive, dismissing their cognitive abilities. This was a misinterpretation. A raven, for example, has a brain that looks quite different than a Capuchin monkey, and is about a third of the size.
But both animals have a similar number of neurons in their pallium, a brain region thatâs associated with cognition. So while corvid brains traveled a very different evolunationary path than primate brains, it was still one that brought them sophitiscated cognition. The next time you spot a crow, you can be assured of its smarts. Just maybe donât give it a bad reason to remember you.