River talk

Peregrine falcon off PA endangered list

By SCOTT RANDO
Posted 12/29/21

There isn’t an abundance of peregrine falcons here. They are not as common in the region as the bald eagle is at the present time.

Both species were thriving during the 1800s and into the …

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River talk

Peregrine falcon off PA endangered list

Posted

There isn’t an abundance of peregrine falcons here. They are not as common in the region as the bald eagle is at the present time.

Both species were thriving during the 1800s and into the 20th century, but both suffered a precipitous decline in population. Like the bald eagle, the peregrine falcon suffered from the effects of chlorinated hydrocarbons, mainly DDT along with its breakdown product, DDE.

DDT was used in the environment from the mid-1940s till it was banned in 1972. Eggs of the peregrine falcon observed during this time were found to have thin shells, resulting in widespread reproductive failure in most regions of the U.S. and other countries.

By 1960, there were no active peregrine nests in PA. DDT was not identified as the cause of nest failures of birds of prey until the late 1960s.

After the banning of DDT, it was found that the DDE levels contained in peregrine eggshell samples were starting to decline. This encouraged recovery efforts to start in PA and several other states in the eastern US.

The Peregrine Fund, based at Cornell University, began a release program in 1974. Early re-introduction efforts (where birds from other areas, or captive birds were released) met with failure; it was found that many of the historic cliff nest sites where re-introduction took place were prone to predation by great horned owls.

Further releases often took place on buildings in urban areas; between 1993 and 1998, there were releases on buildings in Allentown, Harrisburg, Reading and Williamsport. A total of 59 birds were released at these sites.

In 2013, the PA Game Commission published a 10-year recovery plan for the peregrine falcon. This document outlined conservation and protection plans for the species. The ultimate goal was to have a sufficient population of breeding pairs and young production of peregrine falcons so as to be able to de-list the species from the PA list of endangered and threatened species.

Arthur McMorris, a biologist, became the peregrine falcon coordinator 18 years ago, and co-authored the 10-year plan. Last week, I received a letter from him, a part of which I’ll include here.

“The Peregrine Falcon population in Pennsylvania has now recovered: all of the population recovery criteria specified in our state Peregrine Falcon Management Plan have been met or exceeded for four consecutive years. In 2021, 73 nesting pairs of peregrines were confirmed in PA, 22 of them at cliffs. As a result, the Peregrine Falcon has now been removed from the PA state list of Endangered and Threatened Species (i.e., de-listed).”

The peregrine falcon will continue to be monitored in PA for another 10 years, but banding of young will be curtailed in all but a few select sites. There are not many nest sites in our immediate region yet, but some have migrated from northern areas and you may see them any time over the winter. You may even see them catch a bird in mid-air.

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