The world's fastest bird, once driven to the brink of extinction in the United States by now-banned pesticides, is soaring off the endangered species list.

Interior Secretary Bruce Babbitt planned to remove the peregrine falcon from the endangered list today in a ceremony at a Boise, Idaho, center for breeding birds of prey.

At the bird's low point in 1970, only 39 breeding pairs existed in the continental United States--all west of the Mississippi, said Jeff Cilek of the Peregrine Fund. Now, the U.S. Fish and Wildlife Service estimates that more than 1,650 breeding pairs live in North America. Most are in the West.

Dropping the peregrine from the list means it loses some of the strictest protections of federal law, such as shielding its habitat from development. The federal Migratory Bird Treaty Act still makes it illegal to kill the falcons or possess their feathers or body parts without a rare federal permit.

The Fish and Wildlife Service plans to monitor peregrine populations for 13 years to ensure they don't get into trouble again.

The American peregrine falcon is the sixth U.S. species to recover enough to be removed from the endangered species list, which currently includes about 1,200 plants and animals in the United States. The other recovered species are the brown pelican, the American alligator, the Rydberg milk-vetch (a small plant in the pea family), the gray whale and the Arctic peregrine falcon.

While Babbitt cited the 1973 Endangered Species Act as a big factor in the peregrine's recovery, falcon experts say the key to saving the birds was the 1972 ban on DDT and later restrictions on the use of similar pesticides. Peregrines that accumulate DDT and its chemical cousins from eating contaminated prey lay eggs with thin shells that often break, killing the chicks.