Warren Grigsby, age 13, of Nowata, Oklahoma, for his question:

How did the dodo become extinct?

Ecologists expect that more than 100 animal species will become extinct during the coming century. This is one of the heartbreaking tragedies of our worldwide pollution. The last dodo bird died about 290 years ago, when man made pollution was less serious. But it was the same old careless cruelty of man that caused his extinction.

Each creature is shaped to suit his environment by countless changing events, through millions of years. The world of nature can never repeat the long series of changing events, or reverse the adjustments an animal makes to cope with them. In other words, no species can be created more than once. This is the real tragedy of extinction. When the last of a species is wiped out, nothing like it lives ever again.

The dodos were pigeon type birds who spent millions of years adjusting to life on a few windswept isles in the Indian ocean. The frequent gales made flight almost impossible and the birds that tried it were dashed onto the rocky cliffs, usually before they were adults. Gradually this modified the tendencies inherited by each generation. The dodos who survived long enough to produce chicks were those that preferred life on the solid ground.

Eventually, the dodos became flightless birds    and since the weight of flying birds is limited, there was no reason why they should not become bigger and heavier. These pigeon relatives grew to be as big as turkeys. Their unused wing and tail pinions became silly little tufts of fluffy feathers. Their bulky bodies stood 2 1/2 feet tall and they waddled around  on short thick legs and huge flat feet. Large heads and huge curved bills added the finishing touches to their clumsy, clownish appearance.

This is how the dodos looked in 1507, when Portuguese sailors discovered the islands of Mauritius, Reunion and Rodriguez, about 500 miles north of Madagascar. The flocks of dodos living in these forested fortresses felt no reason to fear their human visitors, no reason not to be friendly. But even if some mysterious voice of nature had warned them, they could have done nothing to save themselves.

Visiting sailors and later settlers slaughtered the trusting dodos in countless numbers. Pigs, dogs and monkeys were introduced to the islands and the big, clumsy birds were helpless against these new enemies. The entire dodo population was wiped out. Nature spent millions of years adjusting this species to its special environment. Mankind brought about its extinction in merely 175 years.

Several living dodos were sent to be studied in Europe and one of these was the last of his species. He died in 1681. The Portuguese named them dodos, meaning stupid, because the birds were so trusting. Perhaps history will note that the name dodo should have been reserved for the thoughtless stupidity of mankind. But let's not despair. History also will note that at last some of us are beginning to regret such senseless tragedies    and even striving to prevent them.