Peregrine Falcon Watch 2017
Why are we concerned about Peregrine Falcons?
Historically, the use of DDT (Dichloro-diphenyl-trichloroethane) as a pesticide resulted in a rapid decline in the population. DDT caused eggshell thinning, resulting in the eggshell breaking while being incubated. This resulted in the near extinction of the species. Since the ban of DDT in the 1970s, peregrine falcon populations have recovered significantly and are showing signs of recovery where they haven’t been spotted for decades, such as Harpers Ferry.
Peregrine falcons are protected under the Migratory Bird Treaty Act.
What is the NPS doing?
Resource Management staff at Harpers Ferry NHP have been working to help protect and re-introduce peregrine falcons back to the area for over a decade. In the past few years, a pair of peregrine falcons chose the cliffs of Maryland Heights as a nesting site and the NPS has been monitoring their activity. Unfortunately, the mating pair has not successfully produced a viable clutch and no offspring have resulted.
In February 2017 a team of Natural Resource professionals from Shenandoah National Park worked with protection rangers and resource staff at Harpers Ferry to perform a nest site inspection at two locations on the cliffs of Maryland Heights. The inspection involved an Ecologist from Shenandoah National Park, Alan Williams, rappelling to the observed nesting sites, assessing the conditions and ultimately, adding native stones and gravel to improve site conditions and drainage. Site condition could be one reason why the peregrine falcons have not successfully produced offspring.
Another factor, and the reason for the cliff closure, is that Peregrine Falcons are a sensitive species, on several levels. Human interference, especially during the nesting phase, can drive the mature falcons off, abandoning eggs and fledglings that would be left to die. Specific cliff areas are closed to climbers and a portion of the areas above the cliffs are closed to hikers. The closure is marked with signs and cordoned off with yellow rope. Please respect this closure to give the peregrine falcons a safe habitat to breed and nest.
Peregrine Falcon Facts
Scientific Name: Falco peregrinus
Size: Adult peregrines are about the size of a crow with wings that can span more than three feet.
Weight: Females are larger than males weighing 32 to 34 ounces (900-960 grams). Males are about one-third smaller and weigh 18 to 20 ounces (500-570 grams). At birth, chicks weigh about 1.5 ounces (42 grams), but they grow quickly and eat so much that they can double their weight in just six days. They grow to be 10 times their birth size after only three weeks.
Coloration: Both sexes have the same coloration. In the first year, they are a chocolate brown with lighter streaks on the belly. Adults have slate blue backs and white with black speckling and salmon hues on the breast. Both sexes have a distinctive small black stripe under each eye. Chicks are covered with a soft, white down. Brownish feathers appear in three to five weeks.
Habitat: In the wild, peregrines prefer high cliffs overlooking rivers and lakes where they build their nests. The nest is called a "scrape" which is often nothing more that a small depression in dirt or gravel. They also have been know to set up house on tall bridges, on tall building ledges, and other high places.
Preferred food: Peregrines are determined hunters that fly at high altitudes and often dive on their prey at very high speeds. They mostly feed on birds they catch in mid-air including pigeons and ducks. They also prey on smaller birds such as sparrows, starlings, blackbirds, flickers, jays and doves. A mature peregrine consumes about 2.5 ounces (70 grams) of food each day which is equivalent to two medium-sized birds.
Reproduction and Growth: Peregrines usually begin breeding around two years of age. The male mating ritual includes aerial acrobatics to attract the attention of females. Often the male will kill a bird and present it to the female. Sometimes the male, while flying above the female, will drop his prey which is caught by the female.
She lays a clutch of three to five eggs each spring. The eggs are smaller than chicken eggs and can range in color from a light pink to a reddish-brown. The pair share incubation duties which last about 33 days. At about 12 weeks of age, juveniles begin to hunt and care for themselves. A breeding pair may use the same nest site for many years. Peregrines have been known to live as long as 15 years.
Fast fliers: Their long pointed wings give them a fast-looking appearance. In level flight, they can reach 60 mph. They have been clocked diving, or stooping, at speeds of more than 200 mph.
Last updated: March 1, 2017