Terry Preston, age 11, of Cobourg, Ontario, Canada, for his question:

What are megapodes?

This is a story of turkey birds and large feet, incubators and warm ocean islands. The turkey type birds are called megapodes because the name means big foot. They are the only family of birds that build incubators, instead of hatching their eggs in the usual way. The 20 or so species of the family enjoy life in Australia, New Guinea and many smallish islands of the mid Pacific.

The megapodes are classed with the galliformes, or chicken type birds. Like all their numerous relatives, they scratch and peck on the ground for a living. Their stubby beaks, strong legs and sturdy claws are very suitable for this life style. The group includes shy quails and grouse, turkeys and ptarmigans, proud peacocks and fancy pheasants. Some galliformes prefer the Arctic; the megapodes and many other interesting species prefer the tropics and semi tropics. The smallest megapodes are chicken sized, the largest are as big as turkeys. They have sturdy bodies, very strong legs and extra large feet with extra sharp claws    even for galliformes. In their native haunts, they are called brush turkeys and scrub fowl, moundbuilders and mallee fowl, leipoa and thermometer birds. They are remarkable because they build mounds of debris in which to incubate their eggs. As a rule, the necessary warmth is provided by decaying vegetation. But certain bold parents entrust their precious eggs to sands warmed by underground volcanic activity. In Australia, the enormous mounds once were mistaken for native burial grounds. A heap of earth and vegetation may be 50 feet wide and 15 feet high. It is thought that several generations of parent megapodes scratch and scrape together the ten or more tons of debris to build it. The great pile of decaying compost may be supervised by one male bird in charge of several females. Some observers suspect that certain mounds may belong to just a couple of parents. In any case, both parents are highly sensitive to the temperature of their do it yourself incubator. When it reaches about 95 degrees Fahrenheit, the female selects a site high on the mound and drills deep slanting holes, one for each of her five to eight eggs. When the eggs are covered, the heat of the compost begins to perform its magic. The anxious parents stand by, checking and adjusting the temperature. When the mound pets too hot, the male bird drills ventilation holes. When things are too cool, he adds more decomposing debris.

In a few weeks, the white, thin shelled eggs turn coffee brown. But the chicks are not ready to hatch for at least two months. After such a long incubation period, they are fully developed and ready to go. Though the parents are poor fliers, the chicks take to the air within a few hours. The adult megapodes let them go    and perhaps the youngsters come back later to brood their own eggs in the old family incubator.