If I went out outside and shouted at the chickadees perched at the feeders on our deck, the birds would fly away.
Five minutes later, they'd be back. No harm, no foul.
A couple of years ago the neighborhood crow family discovered our suet feeders. They'd eat all the suet they could reach. I shouted them off the feeder two or three times. They return rarely and cautiously. See me and flee. Crows learn quickly.
Relative to body size, a crow brain is five times the size of a pigeon brain. On the same basis, crow brains are larger than those of chimpanzees.
How smart are they?
A Canadian scientist devised an intelligence measure for birds. It was based on published descriptions of various feeding strategies employed by birds. High on the list were crows, eating as though they were at the State Fair.
At the bottom were quail, birds of routine lives. Chickadees and most songbirds live by routine. Crows, ravens, jays and magpies have evolved to live lives of variety. Variety makes/takes brains.
Crows make and use tools. New Caledonian crows are famous for that. In an experiment they were given a problem: food at the bottom of a bottle. With the bottle they were given straight pieces of wire. The crows bent the wire to form hooks, then fished the food from the bottle. The Internet is full of smart-crow videos.
Also high on the bird smarts scale are ravens, jays and magpies, all members of the corvid family of birds and all found in Minnesota.
I've seen ravens do barrel rolls when flying in a straight line. Flap flap, roll over, flap flap. No reason to do that except for the fun of it. I've watched young crows roll in the grass, pushing at each other. Play is also a sign of intelligence.
A reader wrote me months ago about blue jays coming to his feeders. He thought they were picking up peanuts in the shell to test weight, this one, that one. Heavier peanuts mean a bigger meal. He added weight and marked certain peanuts. Sure enough, heavier peanuts were discovered by trial and error, then taken first. Smart jays.
I've watched jays at our feeders doing the same thing. They'd take those peanuts and hide them for future use. It's called caching. It takes a powerful memory to be successful at that.
Pinyon jays, a western species, will hide thousands of pinyon nuts in the fall, food to be eaten in winter. Researchers found that the jays faced the same compass direction when placing and retrieving seeds, offering precise visual clues. That's smart.
The jays, as do other corvids that cache, kept on eye on other jays in the area. The birds would stealthily move the hidden food item if they thought another bird knew the hiding place. We'd do that; it's a good idea.
While researching smart birds, I ran across a story about vultures. These vultures were observed during war in Rhodesia. They sat on perches near a mine field, waiting for unwitting animals to be blown into a meal.
That's either like a chickadee at a bird feeder or it's smart.
Lifelong birder Jim Williams can be reached at firstname.lastname@example.org. Join his conversation about birds at startribune.com/wingnut.