50 Years After We Dealt W. DDT & Revived The Species, Peregrine Falcon #s Collapsing In At Least 11 Countries

[hatrack]

For the past six years, Gordon Propp, who builds sets for British Columbia’s film industry, has kept a close watch over 13 peregrine falcon nests in and around Vancouver, including 10 on the city’s bridges. A self-described wildlife enthusiast and citizen scientist, Propp has had a lifelong fascination with these raptors. “To see a creature that high up the food chain adapting to an urban environment, to me, that’s quite remarkable,” says Propp.

Watching peregrines (Falco peregrinus) flit about and hunt with their trademark speed, swooping in pursuit of prey at speeds of up to a staggering 250mph (400km/h), is “etched in my mind”, says Propp. But for the past couple of years, most of Propp’s winged wards have been nowhere to be found. Construction and egg predation by clever ravens can probably explain the disappearance at two locations, but he cannot explain why the other nests are empty.

Propp’s observations are hardly isolated. Scientists around the world have been recording plummeting peregrine populations in at least 11 countries. Name any place in the world and peregrine falcons are likely to have soared across its skies. They breed throughout the eastern US and northern Canada, as well as in Greenland, Russia and Scandinavia. They are widespread year-round along North America’s west coast, in South and Central America, Europe, Africa, the Middle East, across Asia and in Australia.

In North America, Skip Ambrose, a peregrine expert formerly with the US Fish and Wildlife Service, has been monitoring the falcons along Alaska’s Yukon River since 1973. He, too, has seen a sharp decline in numbers. In the summer of 2023, Ambrose reported that 20 of 60 peregrine nesting sites were empty, with nearly a dozen more missing a parent. That is particularly notable because peregrines are generally loyal to both their nesting site and their partner.

EDIT

https://www.theguardian.com/environment/2025/mar/13/decades-after-peregrines-came-back-from-the-brink-a-new-threat-emerges-aoe

[Botany]

1. 4 guesses:

Lack of Prey

Environmental Toxicities

Change of habitat

Not a diverse enough gene poll for future generations