For the Birds Radio Program: Peregrine Release
How successful has the Peregrine reintroduction been?
(Recording of a Peregrine Falcon)
The fastest animal in the world, the Peregrine Falcon, is at long last breeding in Wisconsin and Minnesota. Two pairs are nesting on Lake Superior’s North Shore, and at least a few pairs are nesting in big cities, from Minneapolis to Milwaukee and Madison. Before they were extirpated from most of the eastern United States by DDT in the 1950’s, peregrines had discovered that skyscrapers work just as well as natural cliffs for raising babies, and cities supply a virtually endless supply of pigeons, starlings, and House Sparrows, making hunting a simple matter.
Before DDT, there were about 30 or 40 pairs of peregrines breeding in Minnesota’s upper Mississippi Valley and North Shore. The Minnesota Peregrine Project, begun in 1982, set a goal of reestablishing 15 to 20 breeding pairs, half the original level. It is hoped that once this many pairs are breeding again, they will be able to maintain and even increase their numbers without any more human intervention. Cornell University, which began the original research on breeding peregrines in captivity in the 60’s, is coordinating the various eastern state reintroduction projects–their long-range goal is to see 175 pairs breeding in the Eastern United States, again about half of the pre-DDT population.
Even in 1989, Peregrines suffer from human excess. Pigeon fanciers and racers have shot several reintroduced falcons in California, and most wild peregrines still have detectable levels of DDT in their blood. Although DDT was banned in 1972, it is a major contaminant in Kelthane–one of the many toxins sprayed on lawns right here in the Northland. DDT is found in oceanic waters throughout the world, where many Peregrines winter, and is still used heavily on their Central and South American wintering grounds.
Peregrines are probably the most highly evolved of all hunters, with their exquisite eyes, unmatched for visual acuity, their speed, and their powerful talons. High speed photography has demonstrated that Peregrines strike their prey—birds from about the size of starlings to small ducks and coots— with their four toes fully extended. The victim is ripped apart in the impact, usually producing a shower of feathers, and generally dies instantly. Usually the peregrine picks it up on the ground, but occasionally races gravity and catches it on the wing.
The Peregrine Falcon is found world-wide, with the widest range of any bird. It’s also one of the few land birds that flies long distances over the open waters of the ocean—what fear has a peregrine that a gull will knock it into the water? Peregrines show a great deal of variation in their prey selection throughout the world. One breeding male in the eastern U.S. concentrated on Blue Jays, which made up 93% of his diet one season. An Australian female specialized in coots. Some of them are quite adept at hunting shorebirds, and others on ducks. Peregrines are such magnificent predators that many other countries are also actively working to increase their numbers once again. Today is a good day to consider this magnificent symbol of liberty and independence, and to be grateful for one real environmental success story.
(Recording of a Peregrine Falcon)
This is Laura Erickson, and this program has been “For the Birds.”