Crafty crows are smarter than we think

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crow perched on post
By Linda Tanner [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

Several times each year I’m pleasantly surprised when I get a letter or email from a reader asking how to attract more crows. Such letters make me smile.

But thanks to movies like The Birds, many people have a negative impression of crows. In fact, I’m just as often asked how to discourage crows. Crows are large, intelligent and always entertaining to watch. It’s true that they can eat more than their fair share, but it’s relatively easy to control their activity.

Because crows are big, smaller feeders with small perches effectively exclude them. So do tray feeders with low roofs or domes.

On the other hand, encourage crows by simply casting corn kernels directly on the ground, or on open trays. Whether you like or dislike crows, attracting or discouraging them is easy.

Communicating with crows

Put me in the pro-crow camp because they often communicate directly to me. When I’m in the woods and hear that familiar “Caw! Caw!” I start scanning nearby trees. Usually I find the crows near a large tree, and on one of those branches, right where it joins the trunk, perches a great horned owl. The crows continue scolding until finally, thoroughly annoyed by all the fuss, the owl flies off.

During daylight hours, crows have the advantage when they find an owl. At night, the tables turn. A roosting crow is easy prey for a large, powerful owl. Barred and screech owls also prey on smaller birds. That’s why many smaller birds, such as chickadees and blue jays mob owls just as crows do.

Birders use this behavior to find owls during the day. A mixed flock of agitated songbirds usually means there’s an owl nearby. Mobbing seems to signal this message: “We see you. You can’t surprise us, so leave because we’re going to harass you until you do.”

Intelligent birds

Crows belong to an unusually intelligent family of birds, the Corvidae. These intelligent scavengers learn quickly that cars and trucks provide an endless supply of carrion, but they rarely fall victim themselves. And hunters know crows can recognize a gun. Unarmed, you can easily walk within shooting range of perched crows. But carry a gun, and they keep a safe distance. Several times I’ve subjected crows to a simple test.

When I use a walking stick as intended, crows ignore me. But when I sling it across my shoulder like a shotgun, they stay out of shooting range. Despite their superior intellect, however, crows don’t get much respect. Crow hunters kill them simply for sport. Farmers sometimes string their carcasses on fences to send a message.

Yet crows thrive, In the fall, crows are particularly conspicuous. Large flocks gather at dusk and fly to roosts they use year after year. Roost size varies from hundreds or even thousands of crows to, in extreme cases, millions.

Feeding grounds

In the morning, they disperse as far as 50 miles to their favorite feeding grounds. In the spring, flocks break up and crows become surprisingly quiet and inconspicuous. Adults pair off and build a nest in the fork of a large tree. Nests are usually more than 30 feet above the ground.

Throughout the nesting season, pairs are often assisted by “helpers” — nonbreeding offspring from previous years. Helpers collect nesting material, defend the nest from predators and even feed nestlings. Helping is a sophisticated behavior that has obvious benefits for the breeding pair, but it also gives non-breeders valuable experience that they use when they become breeding adults.

The female incubates four to six eggs for 18 days. Young crows remain in the nest for about five weeks before fledging. Crows are classic scavengers, so finding food is never a problem. They eat everything from insects, earthworms, frogs, and small snakes to carrion, eggs, small birds, grains, fruits, and berries. With such a broad diet, crows rank as one of the most successful generalists of the bird world. Here’s one final tip. Put table scraps on a large tray feeder, and crows can save you a trip to the compost pile.

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