Adult falcons have a distinctive “hood” on their head, a gray back and a white throat. -Photo by: KDFWR
The American Peregrine Falcon (Falco peregrinus anatum) experienced severe population decline during the mid 1900’s. This decline was mostly attributable to eggshell thinning caused by the widespread use of the pesticide, DDT. By the 1970’s, populations east of the Mississippi River had vanished, while only a few hundred nesting pairs remained in the western portion of the country. Prior to reestablishment, the last active nest in Kentucky was documented in the late 1930’s.
Starting in the 1970’s, cooperative efforts by both public and private organizations nationwide contributed to one of the most successful species recoveries in history. The recovery of the Peregrine Falcon can be credited mostly to the outlawing of DDT in 1972 and widespread hacking (release of juvenile birds). Hacking efforts in Kentucky occurred from 1993-2003, with 82 falcons released in urbanized areas and 32 released in cliff habitats. Kentucky’s nesting population began to reestablish in 1997, when biologists discovered the first pair of Peregrine Falcons nesting in the wild in decades.
In 1999, the Peregrine Falcon was removed from the Federal List of Threatened and Endangered Wildlife. However, it remains federally protected by the Migratory Bird Treaty Act, and listed as a Species of Greatest Conservation Need in Kentucky’s State Wildlife Action Plan.
Although Peregrine Falcons historically nested on cliffs, nowadays the species will nest on tall manmade structures as well. Abundant prey (pigeons and starlings) coupled with high structures at urban areas in Kentucky provide good habitat for Peregrine Falcons. In attempt to increase nest site availability and productivity, the Kentucky Department of Fish and Wildlife Resources (KDFWR) has placed nest boxes at many locations throughout Kentucky. The Kentucky Transportation Cabinet, as well as several power companies, chemical facilities and building owners have cooperated with KDFWR to provide safe nesting sites for this species.
Figure 1. Peregrine Falcon nesting activity in Kentucky since reestablishment. Nesting success is defined as one of more young successfully fledging from a nest.
Falcon nest boxes are large- over 2 ft wide and over 1.5 ft deep and high. This one is situated on a catwalk of a power stack- over 600 ft high. -Photo by: KDFWR
Nesting locations are monitored annually and the number of young which hatch and fledge (leave the nest) is recorded. The number of known territorial nesting falcon pairs in Kentucky has tripled in the last 15 years from just five in 2004 to 16 in 2019 (Figure 1). Most of these nests are located on manmade structures near the Ohio River between Louisville and Ashland (Figure 2). However, a few pairs have taken up residence in the central portion of the state.
Productivity and survival of individual falcons is monitored through the resighting of colored leg bands, a common method used to monitor many species of birds. When possible, each Peregrine Falcon is fitted with a US Geological Survey (USGS) leg band etched with a unique 9-digit number and a bi-colored band with a unique series of colors, letters and numbers so that the individual can be uniquely identified through a spotting scope. Resighting of leg bands allows biologists to differentiate individuals which are observed nesting, and to verify the origins and history of each banded individual.
KDFWR biologists placed a satellite transmitter on a peregrine falcon in 2015 in order to learn more about the home range and movements of nesting falcons. A report about this study can be found here.
Regionally coordinated post-delisting endangered species monitoring in the eastern United States ended in 2015, when the species was determined to be stable. However, falcon monitoring and management has been continued in Kentucky to ensure Peregrine Falcons maintain healthy population levels and in hopes that the species will recolonize natural habitats.
KDFWR would like to recognize the following companies and agencies that have contributed to Peregrine Falcon restoration and monitoring in Kentucky: