# Bird sense: Crows, pigeons good at math

DRAWING BY DEBORAH DERR McCLINTOCK

Q. How much numbers sense is out there in the "wild kingdom"? Can any animals count to 5, 10, 45, 50...? M. Perkins

A. Counting crows are famous for being able to keep track of up to six hunters lurking in a blind, who try to fool the critters by having two hunters go in, then one back out (2-1 = 1), or four in and three or two out, etc. The birds generally don't lose count until five or six.

For social animals, there is "strength in numbers," says Mark Hauser in American Scientist magazine, such as three male chimpanzees attacking and killing a lone intruder at 3-1, but 2-1 may not be enough. Yet within the same social group, 2-1 may be enough to establish dominance. Rhesus monkeys can figure 2 + 1 and 2 - 1 but not 2 + 2. They seem to count 1, 2, 3, many, says Hauser.

All that's in the wild. What happens when rats or pigeons are "educated" in Skinner boxes? They press the button once and 1 food pellet is released. The same if every three pushes yield one pellet. And even if exactly 24 pushes are necessary, no more, no less, the counters can do this as well. Mon dieu!

Now for the incredible part, says Hauser: Pigeons can count to 45 or 50 pecks for food, 45 on a left button, 50 on a right. In another trial, when a central button lights up, they must learn to peck until the light goes off, at either 45 or 50. Then to get the food, they must recall the count and go without error to either the 45-peck or 50-peck button and push it. "Pigeons can solve this problem too," he says.

Q. When talk turns to nuclear weapons of mass destruction rated in megatons of TNT, how is this destructive power to be pictured? Je ne sais pas. What is a megaton? ­G. W. Bush

A. That's a million tons. First imagine a large truck, capacity 30 tons, then 33,000 such trucks fully loaded to carry the 1,000,000 tons of "payload"–1 megaton of TNT, suggests Art Hobson in Physics: Concepts and Connections. At 15 meters per truck, with no spacings between, the convoy would stretch 500 km (310 miles); for 10 megatons, make that 5,000 km, or trucks all the way across the U.S.

For comparison, the atomic bomb dropped on Hiroshima August 6, 1945, released just 12 kilotons of nuclear energy, or 12,000 tons; Nagasaki on August 9, 20 kilotons. Thus it would take some 50 Nagasakis to equal just 1 megaton!

The largest weapon ever detonated, says Wikipedia: The Free Encyclopedia, was the "Tsar Bomba" (King of Bombs) at 50 megatons, or trucks half way around the world.

Q. For romancing in another nation or culture, would you need to learn new flirting techniques? Or are these pretty much universal? ­R. Montague

A. They're instinctive, no practice necessary, says Diane Ackerman in A Natural History of Love. It doesn't matter if you're in Holland, Taiwan, Indonesia, or Amazonia.

"The eyes– a little glance, glance down, glance back with a little smile– that will work anywhere," says University of Michigan psychologist Phoebe Ellsworth. But a word of caution: American guys are a lot more blatant than men in many other cultures, and while the women may appreciate this, their fathers and brothers won't. You could find yourself in deep trouble by being too friendly.

"In many cultures, flirting with strangers just isn't done," Ellsworth says. Physical closeness, parallel postural orientations, and touch also are universal, but there are differences in how these are used, says University of Connecticut professor of communication sciences and psychology Ross Buck. In a famous example, couples at cafés were observed to touch 180 times per hour in San Juan, couples in Paris 110 times, and in London 0!

In other words, romance "display rules" vary widely: So, when in Rome, do as the Romans dounless, of course, you're in a racier mood and couldn't care less about conforming.

Send Strange questions to brothers Bill and Rich at strangetrue@compuserve.com.

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