Falcons find homes among man-made structures

A peregrine falcon flies from its nest at the Conowingo Hydroelectric Generating Station, or Conowingo Dam, in Conowingo, Maryland, on March 11, 2015. The dam sits across the lower Susquehanna River, about ten miles from where the waterway meets the Chesapeake Bay.

Just below the dam is an area well-known for bird-watching—most famously for bald eagles and great blue herons, drawn there by the high availability of fish around the dam’s outflow. Also known to frequent the site are peregrine falcons, whose preference for hunting by diving leads them to nest high on natural and man-made structures, like the nearly-100-foot-tall Conowingo Dam. Highly territorial, only one to two birds typically nest at the site at a time.

Although peregrines can be found on every continent except Antarctica, the falcons are uncommon in many parts of their historic range: in the mid-20th century, widespread pesticide use led to a drastic decline in peregrine falcon populations. By 1964, nesting peregrines were extinct in the eastern United States.

In 1979, a recovery plan was established to restore breeding peregrines to the eastern U.S. Through the program, 174 pairs of nesting peregrine falcons were established by 1997, with at least 27 pairs originating from the Chesapeake Bay region. By 1999, the peregrine falcon was removed from the Endangered Species List—and in the years since, the Chesapeake Bay has reestablished itself as an important region for nesting and migrating peregrines.

Peregrines in the Chesapeake region are perhaps best-known for their tendency to nest on man-made structures: the Chesapeake Bay Bridge and Francis Scott Key Bridge, as well as skyscrapers in downtown Baltimore, Richmond, Harrisburg and other cities. Each spring, the Chesapeake Conservancy streams live video of a pair of peregrine falcons nesting on Baltimore’s Transamerica Building. Last year, peregrines “Boh” and “Barb” raised three young falcons at the site.

Learn more about the peregrine falcon.