Why these nesting falcons mean so much to EDF
A young peregrine falcon in the nestThis unfledged nestling is also known as an “eyas." It takes chicks about six weeks to learn to hunt.Glenn Nevill
A hatchling gets measured before bandingAlong with banning the pesticide DDT – which weakened eggshells – an aggressive banding and tracking program has helped restore peregrine falcon populations.Glenn Nevill
Finding plenty of food in the cityThis pair is nesting on a San Francisco building, taking advantage of ample pigeon populations.Glenn Nevill
Peregrine falcons are superb flyersThe incredible aerial maneuvers of peregrine falcons make them intoxicating to watch. They are aggressive, though, and close contact should be avoided.Glenn Nevill
Transferring prey mid-airPeregrine falcon pairs can cooperatively hunt to catch their prey, and even transfer it to one another in mid-flight. This San Francisco-based pair often grabs pigeons and doves.Glenn Nevill
Peregrine falcon turning headPart of what makes peregrine falcons such adept hunters is their ability to crane their necks around and use their large eyes to hone in on prey.Glenn Nevill
By Charles Wurster and Art Cooley
When we helped found EDF 45 years ago, we could not have imagined that a mother peregrine falcon would be spotted feeding her chicks 30 stories above downtown San Francisco, in the same building where most of EDF's California staff works.
That's because this magnificent bird – which can exceed 200 miles per hour in flight, making it the fastest creature on the planet – experienced a population collapse during the middle of the last century due to the pesticide DDT.
DDT threatened the survival of peregrines, American bald eagles, and other predatory and fish-eating birds. It caused the birds to lay thin-shelled eggs, which broke prematurely in the nest.
Nearly wiped out, now recovering
Peregrine populations plummeted by an estimated 80% in North America and Europe, especially in the eastern U.S. where peregrines were exterminated as a breeding species. In California, there were only two known breeding pairs.
EDF was founded in 1967 and immediately tackled the DDT problem. Lawsuits were filed in New York, Michigan, Wisconsin, and Washington DC. Dozens of world-class scientists – ornithologists, ecologists, toxicologists, carcinogenesis experts, and insect control specialists – testified in multi-month hearings.
In 1972, William Ruckelshaus, first administrator of the US Environmental Protection Agency, ordered a ban on DDT in America.
Today, the recovery of these birds has been nothing short of spectacular. Peregrines have rebounded to their former numbers and the US Fish and Wildlife Service has removed them from the federal list of threatened and endangered species.
Birds rebound after DDT ban
Peregrine falcons are one of several bird species that have made dramatic recoveries since the ban on DDT. Others include:
American bald eagle, removed from the federal list of threatened and endangered species in 2007.
Brown pelican, removed from the federal list of threatened and endangered species in 2009.
Osprey populations, after drastic declines in the 1950s and 1960s, have made significant recoveries.