Improved Birdbrains

Improved Birdbrains

The term birdbrain is commonly used to describe a nitwit, a stupid or silly person. Birds earned this reputation because some exhibit little intelligence and engage in life—threatening behaviors that are downright stupid. Woodpeckers will hammer holes in a tree and stuff in acorns and nuts for the winter. They don't notice when the tree is quite thin or is the wall of a cabin, so hundreds of food bits fall to the ground or indoors, inaccessible to the hungry bird. The woodpecker may be upstaged by the hoatzin of the Amazon valley, which builds its nest on low branches overhanging the water. At the first sign of an intruder the hoatzin dives to the safety of the water but seems unable to understand that the intruder may be a crocodile resting directly under its nest with jaws agape.

Among species of birds that are downright intelligent are the 105 members of the Corvidae family, which includes jays, magpies, ravens, and crows. The large, noisy, mischievous common crow appears to be the Phi Beta Kappa of the feathered world. Of all bird brains that have been studied, the crow has the largest cerebral hemispheres relative to body size. This denotes an excess of brain power and explains why crows can learn even faster than monkeys. They can be taught to read clocks and to count, and they are seldom fooled a second time by a scarecrow.

Crow ingenuity enables them to flourish despite incessant attempts to eliminate them, for they are something of a pest. Clearly the crow is a nuisance to a number of animals, as it amuses itself by tweaking tails of birds, pecking at sleeping cows and dogs, and engaging in other annoying but harmless fun. Some of the crow's devices involve intricate problem solving. In Finland, people fishing through holes in the ice often return to their line to find a crow pulling it in with its bill. Then the crow returns to the hole, walking on the line to keep it from sliding, and retrieves the fish at the end of the line.

In recent years crows have been flourishing as urbanites, especially since their discovery of the four—wheeled nutcracker. Any patient bird—watcher can observe crows sitting on a tree branch near a road and waiting for an oncoming car or truck. Just as a car approaches, they will fly over the road and drop nuts in front of the vehicle. The car will, of course, run over the nuts, thoroughly cracking the shells. The bird then dines on the exposed nut meats. Such meals are not without hazard. If the road happens to be a busy freeway, the crow must grab and fly. The clever crow that indulges in a leisurely lunch often becomes roadkill.

In the city parks of Japan the green—backed herons obtain their food without exposing themselves to danger. They drop small twigs into a pond and watch as the twigs float a short distance. They drop a few more until one of the floating twigs attracts the attention of the small minnows that inhabit the pond. Thinking it may be something to eat, the fish swim up to the twig. Their investigation doesn't last long because the heron quickly snaps them up when they come into range.

The tropical bee—eater puts itself in jeopardy each time it enjoys its one—course meal. But it has perfected a ritual that renders the bee a juicy, nonthreatening morsel. The bee—eater catches a bee in midair by grasping it around the waist with the tip of its beak. Then it bangs the bee's head several times against a nearby hard object and in the process shifts its grip to just in front of the stinger. The bird rubs the stinger vigorously against a solid object until it breaks off or the venom escapes. Finally the bee is almost suitable for eating, so the bird juggles it back to its original position, bangs its head a few more times to make sure it's dead, and gulps it down.

From the book: 
Petrified Lightning