Peregrine Falcon on its Way to Recovery

Peregrine falcons in California are on their way to recovery, thanks to effective management of the threatened species, according to a new study.

American peregrine falcons (Falco peregrines anatum), once widespread across North America, faced extinction in 1975 due to popular use of the deadly insecticide DDT, which caused young birds shells to become thinner.

In 1992, biologists proposed to stop rearing young birds in captivity and instead place them in wild nests to boost recovery. Thanks to these efforts, the world's fastest bird is on the right track, though falcon numbers are lower than hoped for.

"The challenge was to come up with data," Tim Wootton from the Ecological Society of America (ESA) said in a statement. "Once a species falls off the endangered species list, there is not a lot of funding to track how management, or lack of management, is doing," he said. "There was limited data that was appropriate being collected on the falcon, so we turned to a couple of well-known bird censuses that cover wide geographic areas."

According to Defenders of Wildlife, there are an estimated 1,650 breeding pairs in the United States and Canada. This is great news to wildlife advocates considering that there were just 159 breeding pairs of American peregrine falcons in 1975. Chicks often did not survive in thin shells made fragile by a metabolite found in DDT.

But once both Canada and the United States banned agricultural use of DDT, and the peregrine was listed as endangered in 1970 under the original Endangered Species Act, their numbers steadily improved. The US Fish and Wildlife Service removed the falcon from endangered species protection in 1999.

These speedy birds - capable of diving at up to 200 mph - have blue-gray wings, dark brown backs, a buff colored underside with brown spots, and white faces with a black tear stripe on their cheeks, Defenders of Wildlife describes. The Breeding Bird Survey, in collaboration with the ESA research team, is asking avid bird watchers to keep their eyes of the skies, and record observations so as to monitor the recovery of this American falcon.

The findings were published in the journal Ecological Applications.