40 years worth of study followed the imperiled peregrine falcon recovery in Alaska and the news is good.
Peregrine falcons are the world’s most widespread bird of prey, living within ecosystems as diverse as the Arctic tundra, the sweltering desert, and even among the skyscrapers of cities small and large.
In 1973 the peregrine population in east central Alaska was in an 80 percent decline and had only 11 breeding pairs left. In 2014 that number had burgeoned to some 60 pairs and counting.
U.S. Fish and Wildlife Service wildlife biologist Skip Ambrose and his wife, ornithologist Chris Florian, have been studying falcons for one of the longest running bird studies in U.S history for 40 years and counting.
Ambrose said, “This 40-year recovery is really wonderful, but we think the next ten years might be even more interesting, I’m shooting for fifty years, at least.”
As with many bird species, including our national symbol the bald eagle, peregrines began to fall victim to the widespread use of DDT which, among other things, causes bird eggshells to become dangerously thin and break prematurely.
By 1970, the U.S. Fish and Wildlife Service had listed the American peregrine falcon as an endangered species, and two years later the EPA severely restricted the use of DDT in the United States. After that, peregrine falcons mounted a fierce comeback in the late ‘70s.
In those years Ambrose was well into his study of the iconic bird. He and a rotating crew of biologists started doing twice-yearly studies of the same 165-mile stretch of the Yukon River, involving parent falcons and their hatchlings.
In the 70s and 80s the wildlife biologist and his colleagues would climb the cliffs to tag and band birds with radio transmitters. One of the immediate findings was the profound defense mechanism of parent birds that would dive-bomb researcher’s heads with their talons.
Ambrose said, “I started wearing climbing helmets, and not because the climbing is dangerous.”
Among the many discoveries gained by the bandings was the length of their winter migration flights to places like the southern U.S. and as far as Argentina. Also learned was their longevity- most averaged seven to eight years of age, but some lived until 17.
Because Alaskan falcons dine on over 100 species of birds and are a keystone species, researchers use the apex predator as a long-term vital sign of the ecosystem’s viability and health. With the bird’s long term health at such levels, the Alaska Department of Fish and Game may soon allow falconers to capture some small amount of young birds to ply their sport, as falconry is permitted in most of the state.
In 1999, the peregrine falcon was removed the Endangered Species list, but make no mistake- they continue to face threats in Alaska and elsewhere. Mercury, released by the burning of fossil fuels, continues to accumulate in falcons’ bodies. Peregrine falcon populations could also dwindle in response to things like climate change, diminishing winter habitat, and a reduced supply of prey birds.