Crows and Ravens

The class of birds known scientifically as corvidae includes crows, ravens, magpies, nutcrackers, and jays. In each of these species, the brain-to-body ratio equals that of dolphins and nearly matches humans. These unique birds are more intelligent than eagles, hawks, and owls. Follow along as we study these remarkable avians and see why they're called smart!

THE LOWLY CROW

• Crows have the largest cerebral hemisphere relative to body size of any member of the bird family, and they show it off in a variety of ways. They will, for example, enjoy playing a game that human observers call “toss,” where one crow will drop a twig while in flight and another will swoop and dive to catch it mid-air. They have been known to juggle things between their beak and feet while lying on their backs, and even play friendly games of “king of the mountain.” They have also been known to playfully hang upside down from a wire with wings outspread, using only one foot to hang on.

• Crows will stay in mated pairs till death. Courtship is elaborate, with much bowing and dancing done by the male. Finally he offers her a bit of nesting material as a hint of what he has in mind. The female will lay four to six eggs, and the male provides the groceries while she does the incubating. The mortality rate of baby crows can be as high as 70%.

Crows will stay with the same mate for life.

BIRD LANGUAGE

• Members of the corvid family can imitate many sounds just as parrots can. One ornithologist noticed that his captive jays not only repeated words and whistles they heard from him, but they also barked when they saw a dog; meowed when they saw a cat; and hooted when they saw an owl.

• Although ornithologists have identified about 300 different crow “words,” they have found that one crow cannot understand the dialect of another crow from a different part of the country.

Crows have about 300 "words" in their crow-language, and even feature different dialects based on their regional territory.

• Ravens seem to have “names” for each other and will call out to them when separated.

FEEDING HABITS

• A scientist put an animal carcass out where ravens could find it, then broadcast over a loudspeaker the typical call a raven will give to alert others that he has found a source of food. Just 20 seconds later, a single raven flew to the carcass, inspected it, and left. Two minutes later, 29 ravens were gathered around but did not touch it. They too flew off, but the next morning 40 ravens gathered around the carcass, and only then did they began to feed. Ravens prefer to feed in large groups around food to better protect them from coyotes and other carnivores that also want to feed there.

• A captive jay was fed two kinds of grasshoppers simultaneously. One was edible; the other was poisonous. The jay became ill from the poisonous grasshopper. Later, when he was offered the same two kinds of grasshoppers, he refused the poisonous one and ate only the edible one. Researchers do not know how the crow was able to tell which grasshopper was the one that caused his illness.

• Researchers watching crows drop snail shells on rocks to crack them open determined that the height the crows dropped them from was exactly the height needed to crack them. To drop them from a lesser distance would have meant wasted energy when they failed to open; dropping them from a greater height also wasted energy by extra flying and increased the chances the snail would bounce into the water. The crows also swished the snails in water to wash away the undesireable bits of shell.

• Many crows, unable to break open tasty acorns, drop them on the pavement of a street and wait until a car runs over them. They even show an understanding of stoplights by waiting and looking both ways until it’s safe to hop out and retrieve the nut.

• Ravens that have found a complete carcass are unable to open it to reach the meat. They have been known to go in search of a wolf or coyote, then guide it back to the meat so that it will have a chance to eat the leftover scraps.

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• Jays usually stash their food in hiding places underground. In the winter, they are able to retrieve their food even when it is covered by snow to a depth of eighteen inches. The gray jay is able to hide its food by gluing it with saliva to the bark of trees, making it easier to retrieve in winter months. A single Clark’s nutcracker can stash between 22,000 and 33,000 seeds in up to 7,500 different places in a single season.

• Although crows, ravens, and jays are omnivorous and will eat anything including carrion, they never kill their own prey, unlike hawks, eagles, and owls.

REMARKABLE INTELLIGENCE

• A man in Washington once tossed crackers to a raven until the raven was full and could eat no more. The raven wanted to take more crackers back to its cache, but it could pick up only one cracker at a time in its beak. By the time it got back to collect the next cracker, other critters would have stolen the rest of the food. The man was amazed to see the raven solve the dilemma by shoving the crackers one atop another into a nearby snowbank. When he had six or seven crackers stacked up, the raven was able to carefully pick them all up together and fly off with the entire bunch.

• A raven being attacked by a falcon got away when it flew between two narrow strands of barbed-wire fence. Following close behind, its persuing predator had a wider wing-span and was abruptly snagged in the wire as the crow flew away to safety.

A section of barbed wire fence similar to the one used by a raven to outsmart, and out maneuver an attacking falcon.

• A captive crow living at the Allee Laboratory of Animal Behavior was normally fed a moistened mash. Sometimes keepers would forget to first wet the food down before setting it out. Since the crow needed the added moisture to help him swallow the food, he would pick up a small plastic toy cup, hop over to a water trough and fill it with water. He then took it back to the food dish, and dumped the water on the mash. If the cup spilled en route, he would immediately return to the water and start over again.

• In Finland, an observer watched a raven that was quietly eyeing ice fishermen from a distance. It watched the men bait the hooks, drop the lines into several scattered holes in the ice, then wait until a signal flag bobbed, indicating that a fish was on the line. They would then haul up the line and collect the fish in a bucket.

An ice fisherman keeps a watchful eye on the bobbers in the holes on a frozen lake.

• While the fishermen were occupied at one of the holes, the raven saw the flag bob down in another hole. It quickly hopped over and tried to pull the line up by grasping it in its beak, but it couldn’t pull the line up far enough. So it pulled the line as far onto the ice as it could, then stood on it to keep it from slipping back into the water. It kept side-stepping its weight on the line all the way back to the fishing hole, where it grasped the line in its beak and backed up again. It did this over and over until it finally pulled the fish out onto the ice. The clever raven promptly dragged it off and began pecking away at his freshly caught meal. 

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