Peregrine Falcons at Echo Park
Peregrine falcons are a medium-sized bird of prey, roughly the size of a crow. Although males and females are identical in appearance, the female can be a third larger than the male. These previously-endangered birds nest on high, remote cliff ledges in Dinosaur's canyon country.
In the late 1970s, Dinosaur NM was home to four peregrine falcons. Peregrine falcons, identified as an endangered species in 1970, were on the decline across the United States, thanks to the effects of the pesticide DDT. In 1974, Colorado began a peregrine falcon recovery program; two years later, Dinosaur National Monument joined the effort.
As part of the recovery program, adult peregrine falcons at Dinosaur NM became foster parents to young birds. To protect thin-shelled eggs, biologists collected eggs from nest sites and replaced them with peregrine chicks from a breeding facility. Researchers incubated the eggs and cared for the young after they hatched. Although fostering did not eliminate normal chick mortality, it did help to maintain normal brood sizes during the period of eggshell thinning.
Throughout the 1980s, captive-bred peregrine falcons were also released at Dinosaur NM in a process called hacking, which takes place over several weeks. Young peregrines are placed in specially equipped boxes on a cliff ledge and are fed through a chute. When the birds are old enough and strong enough, the box is opened. As the young peregrines learn to hunt, the human-provided food is reduced. Eventually, the peregrine falcons become fully independent.
Within a short time, peregrines that had been fostered or hacked at Dinosaur began returning to the monument after their annual migrations, establishing eyries, and hatching their own chicks. Programs similar to the one at Dinosaur have helped peregrine populations recover across the country: according to the U.S. Fish and Wildlife Service, there were 324 known nesting pairs in 1975 and today there are between 2,000 and 3,000 pairs of peregrine falcons in North America. The peregrine falcon was removed from the list of endangered species in 1999.
