The Woods Are Full Of Star Maps

I didn't recognize her species, so I assumed her to be an immature female that was just beginning her first migration. I smoothed the feathers on the little head. Her brain was smaller than a pea, yet it contained all the information necessary to be a proper warbler: how to fly, find food, and reproduce.

Next spring she could have built her first nest without her mother or any other bird showing her how, and she would have made it just right. It is as though she would have taken a little manual entitled "How to Build a Nest" out of a cubby-hole in her tiny brain, then opened its brand-new pages to Step One, which begins, "Select a piece of dead grass about two inches long..."

But this bird was so young that she hadn't even discovered a lot of the "how-to manuals" in her brain. One rather lengthy instruction booklet would have been "How to Migrate from Maine to Venezuela in the Fall." With it would be a compass, a clock, and even star maps. Most small birds migrate at night, and from experiments with birds released in planetariums, biologists have found that birds do actually use certain stars to guide them on their migration. This means that a way of keeping time is needed because the stars rotate through the sky just as the sun does.

Birds also seem to be sensitive to the earth's magnetic field. Biologists discovered this by placing tiny magnets on the heads of homing pigeons. While wearing the magnets, the pigeons could not return home as well. It would be similar to my trying to use a compass while I had a magnet in my pocket. The compass would point to the magnet, rather than the North Pole.

From experiments like these, it now seems that many birds use a combination of landscape features, magnetism, and the stars when they migrate long distances.

I would need weeks to learn to navigate by air to Venezuela, if I ever could (My trigonometry is very weak.), but this little bird was hatched knowing how. And all that information was packed into a bit of brain tissue too small to see.

So I had in my hand that autumn morning a complete set of star maps on how to get to Venezuela, all neatly packaged in a tuft of colorful feathers. I felt a lingering melancholia about them fading away, unused. My only consolation was that on this incredible, profligate planet, the woods are full of star maps.