Living with wildlife: Keeping up with the corvids

By Gary Raham
Nature Writer

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Crows, ravens and jays are birds that people love to hate. Cheerful rogues that they are, they steal food, laugh in your face and defy you to get the best of them. Magpies, also members of the family of corvids (corvidae), can be obnoxious, too, but they dress with white trim to offset the somber black.

As an immigrant to the Rocky Mountain west from Michigan, I can remember being pleasantly startled to see my first magpie as it unfolded and flew away. "Oh yeah," someone said, "that's just a magpie. You must be a Midwesterner."

My family's first camping trips introduced us to the camp-robbing gray jays and blue stellar jays of the mountains. After our cottonwoods got large enough to provide some perches and shelter, blue jays came to call around the yard and feeder. In the spring, small flocks consisting of one female and her paramours frolic around, the males imitating everything their intended does until she deems one of them fit enough to be husband material. Then they pick the neighbor's pine tree to nest in and skulk around quietly while the youngsters are vulnerable.

Now and then a crow shows up. The only ravens I've seen have been in national parks, where they set up little concession stands and induce primates to feed them. Crows and ravens, with their intense stare and dark colors, bring a somber note to the party, not only for their funeral director appearance, but because they are scavengers not only of breadcrumbs, but carrion. Historically, they've always trailed after armies, knowing a banquet was soon to be served, and they are always first on the scene after plagues and natural disasters.

In the 19th century, many U.S. states put a bounty on crows for their grain thievery. A good many birds were exterminated, but farmers soon discovered that insect damage to crops increased greatly. Crows and ravens actually prefer insects to grain. One solution to this problem is to give these birds a share of the action. A planting ditty that may go back to the days of the Pilgrims says, "One for the cutworm, one for the crow, one for the blackbird, and three to grow."

Of course, you might try intimidation. The English word scarecrow originally applied to a person or "scarer"--often a child--who ran around banging pots or knocking sticks together while new seeds lay invitingly on fresh furrows. Only later did someone come up with the idea of stuffing old clothes with hay and streamers with the hope that it might deter the attentions of at least some of the dumber birds. It usually doesn't take long for crows and ravens to figure out that scarecrows make great perches between snacks.

For some time now scientists have suspected that corvids are even smarter than we thought. (See "Some dumb animals are pretty smart" in the February issue of the North Forty News.) Alex Kacelnik has been studying tool use in New Caledonian crows. (See http://users.ox.ac.uk/~kgroup/) In 2002, he gave a test to crows Abel and Betty, who not only passed the test, but flat out aced it. He placed a basket of food with a handle in a glass tube and offered the crows a straight wire and a hooked wire to see if they could figure out that the hooked one could be used to pull the basket out of the tube by its handle. Abel snatched the hooked wire right away and showed he knew how to use it. But Betty wasn't deterred. She grabbed the straight wire and bent one end to make a hook--not just in one trial, but several times using different techniques. She, too, knew how to use it.

Experimenters Bernd Heinrich and Thomas Bugnyar also have a high opinion of ravens. They believe their experiments, where a raven has to retrieve a piece of meat suspended at the end of a string by reeling up the string in stages, shows problem solving abilities akin to those of our primate relatives, the chimps. Other experiments show that their social skills include the ability to recognize individuals (human or crow), and remember what to expect of them during future encounters. Kacelnik puts his New Caledonian crows in a tie for second place with chimps for tool use. They use four different tool types, which are produced in a series of manufacturing steps and have complex shapes. "The chimpanzees' distinction is to be expected," he said, "because only six million years (or 250,000 generations) separate them from humans, but the fact that a bird shares the second place is surprising--the most recent common ancestor of birds and humans lived about 310 million years ago (170 million generations)."

In a delightful book called simply "Crow," Boria Sax writes "crows often give an impression of sublime indifference to people, as though waiting patiently for the era of human beings to pass." Poe's raven crying "Nevermore" fits well with that melancholy notion.

The Romans had a more optimistic view: "Cras," their word for the cry of the raven (ravens, crows, and other corvidae were often lumped together) meant "tomorrow." They interpreted the raven's cry as one of eternal hope. It also seems like the perfect cry of the procrastinator. Just wait one more day to get that garden planted while you sit and watch the corvids argue at the feeder.