Peregrine Falcon

Peregrine falcons (Falco peregrinus) are found throughout the world (except Antarctica) and have been very popular throughout history. They were prized during medieval times for their hunting prowess in the sport of Falconry. They continue to capture the fascination of many people due to their flight skills, hunting ability, and mystique.

Endangered Species

In the United States, Peregrine falcon populations declined sharply between the 1940s and 1960s due to the widespread use of the pesticide DDT and several other factors. DDT was most damaging to peregrine reproduction due to egg-shell thinning, egg breakage, and hatching failure. DDT was banned (1972), but the peregrine was placed on the endangered species list in 1973.

Reintroduction and Recovery
Surveys done in the late 1970s found no occupied peregrine nest sites in Idaho, Montana, or Wyoming. Reintroduction efforts in these states began when the Peregrine Fund released 11 juveniles at three sites in the Jackson Hole area in 1980, and 4 juveniles in the Centennial Valley of Montana in 1981.

By the late 1980s nearly 100 pergerines had been released in Grand Teton and Yellowstone National Parks. By 1994, 28 had been released at Bighorn Canyon.

In Bighorn Canyon
The 70 miles of steep canyon walls along Bighorn lake appear to provide suitable peregrine nesting areas and abundant rock doves and other prey. Five eyries have been identified since 1994, one of them near the Devil Canyon overlook. The three sites that were active in 2007 produced a total of eight fledglings. The Peregrine is considered to be recovered in the Greater Yellowstone area.

Behavioral Characteristics
Feeding: Hunts most vigorously at dawn and dusk in open areas like shores, marshes, and valleys. Hunting is often accompanied by a series of sharp, aggressive, territorial calls, "kee, kee, kee, kee, kee—kee, kee, kee, kee, kee." Plucks feathers from the prey as it feeds.

Strikes: Usually in mid-air, knocking the quarry to the ground. Less commonly, it will strike and grab prey and fly away.

Nesting: Mostly on precipitous cliffs, but will also nest under suspension bridges and atop tall city buildings. Eggs are laid on a sand- or gravel-covered ledge with a depression that has been scratched in preparation for the clutch. This area is called a scrape.

Physical Characteristics

• Long, pointed, sickle shaped wings
• Small head with dark "sideburns"
• Crow-sized, female larger than male
• Large feet - called "big-footed falcon"
• Adult plummage - white breast, dark gray back
• Immature plummage - streaked breast, brown back

(Sources: include Greater Yellowstone Science Center Factsheet)