PEREGRINE FACONS A TENACIOUS SPECIES

ST. LOUIS -- The death of a peregrine falcon found in St. Louis recently illustrates the difficulties that face this federally endangered bird. But the survival of another falcon found in

Portage Des Sioux, Mo., demonstrates the species' tenacity, and its progress toward recovery.

Mike Cooke, at the World Bird Sanctuary in St. Louis, said the peregrine falcon that turned up there Sept. 26 came from Greenland. The bird was extremely weak when found and died within 36 hours of arriving at the WBS. It wore a leg tag that allowed Cooke to learn a little about its life history. It hatched earlier this year in western Greenland. Workers with the Zoological Museum of Copenhagen, Denmark, banded the bird in its nest in July. Peregrine falcons from that area typically spend the winter in Peru, and Cooke said the bird probably was on its way to South America.

Cooke said tests conducted by the U.S. Fish and Wildlife Service showed that the falcon died of poisoning by one of a group of pesticides known as organophosphates. It probably contacted the poison before arriving in St. Louis. Cooke said the falcon probably got the poison by eating another bird that was suffering from organophosphate poisoning.

The injured falcon that survived turned up at Portage Des Sioux. Cooke said the bird's broken wing probably was suffered when it collided with a stationary object, as sometimes happens with young falcons. After initial treatment at the WBS, the injured falcon was transferred to a raptor (bird of prey) rehabilitation center in Minneapolis, Minn. That facility is equipped to perform corrective surgery on the broken wing. Cooke said that bird probably will be able to return to the wild.

Peregrine falcons once ranged all across North America, though they probably were never numerous.

These superb hunters suffered a near-fatal blow in the 1940s and 1950s, when DDT and other organochlorine pesticides came into widespread use. These "persistent" chemicals break down very slowly in the environment, and build up in the bodies of predators, which eat other animals exposed to pesticides. The concentrations seldom caused direct deaths of adult peregrine falcons, but impaired their ability to reproduce.

One obstacle to the falcons' recovery is the difficulty it has in the recolonization of its former range. To help the birds clear this hurdle, the WBS and the Missouri Department of Conservation have released dozens of young peregrine falcons in the Kansas City and St. Louis areas.

Peregrine falcons released in Missouri have turned up in a half dozen cities as far away as Toledo, Ohio -- thus living up to their Latin name, "peregrinus," which means "wandering." However, some have stayed in Missouri. Birds released by MDC and the WBS have nested in Kansas City and St. Louis.

Conservationists hope to see more nest in Missouri as the number of mature falcons from release programs here and in other states grows.

Peregrine falcons have been sighted around Jefferson City, prompting MDC to place nest boxes for them on the State Capitol and the Jefferson State Office Building.

The peregrine falcon is one of a handful of raptors commonly seen in Missouri that prey on other birds. Others include the sharp-shinned and Cooper's hawks and the Merlin. The Merlin and sharp-shinned hawk are smaller than peregrines, which may measure 15 to 20 inches from head to tip of tail.

The Cooper's and sharp-shinned hawks are woodland hawks, whereas the peregrine and its small cousin, the Merlin, are falcons with pointed wings. The falcons prefer open spaces and dive on their prey from high altitudes.

Peregrines are notable for their spectacular speed and hunting ability. They can reach speeds in excess of 200 miles per hour when diving to catch their prey.