Andrew L. Monroe, age 13, of San Francisco, California, for his question:

What is pigeon's milk?

Today's question arose from an urgent problem. Andrew and his friend Pike removed two white eggs from what they assumed to be the nest of a pigeon family. Mr. Scroggie, their science teacher, promptly popped them into an incubator and everyone waits breathlessly for Hatching Day. In the meantime, research was done on the care and feeding of baby pigeons. Their natural diet is pigeon's milk and the formula poses quite a problem.

Let's get one thing out of the way before we approach the problem. The only animals that yield milk as we know it are the mammals    and birds are not mammals. So the preparation of a formula for baby pigeons from cow or goat milk, or even camel or reindeer milk is out of the question. This is too bad because ordinary milk would then have solved the problem. Actually, the true state of affairs is far more complicated and, sad to say, it may prove to be a hopeless challenge.

The term pigeon's milk applies to partially digested food in the crops of the parent birds. The adult birds prepare it with no trouble at all    but they are not about to reveal their secret recipe, especially to kind hearted nature lovers who take their eggs. The raw materials of weed seeds, corn, oats and other grains are the pigeon's daily menu.

The food is gulped down whole, partially digested into a sort of milky soup and stored in a pouch called the crop. Assembling the assorted seeds is no problem. But it is not likely that the baby pigeons can swallow or digest them. The partial digestive process requires the assistance of several biochemical~enzymes that may be peculiar to pigeons. Possibly a top notch biochemist or molecular biologist may know these involved secrets and even be able to suggest a method to duplicate them.

In this case, the proper formula could be prepared for squirting when the baby chicks open their hungry mouths. If this is impossible, you might try feeding them a mushy diet of cooked grains and cereals. Let's hope to goodness it works. If it fails, the only other possibility might be to enlist help from pigeon foster parents. These birds are devoted parents and both of them prepare and feed the pigeon milk formula to their famished youngsters. Most likely you have already decided that next time the wisest, and no doubt the kindest, course of action is to leave birds' eggs where they belong.

If your man made cereal milk fails, you might select a pigeon populated neighborhood roof and take a chance on putting your starving chicks in foster homes. However, there are only a couple of chicks in a pigeon family and maybe the parent birds can count to two. Place them in different nests with chicks of the same size    and hope that the parent birds will accept a third hungry mouth to feed.