The peregrine falcon is a state endangered species. It was federally endangered also, but it was delisted in 1999. Prior to 1960, there were over 350 nests in the eastern U.S. By 1964 not a single peregrine nest was found in the eastern U.S.; and in 1975, only 39 peregrine pairs remained in the lower 48 states. Peregrine Falcon
DDT pesticides were found to be the main cause of the decline. The pesticides were ingested by birds who ate insects, who in turn were eaten by peregrines. With each step up the food chain, the negative effects increased. The pesticides inhibited the peregrines’ (and bald eagles’) ability to produce enough calcium for the eggshells. This caused vast reproductive failure. Eventually there were no young to replace the adult birds, and the population plummeted.
The dangers of DDT were eventually recognized, and the pesticide was banned from use in the U.S. in 1972. Thus the peregrine has already once been proven as a valuable indicator of the quality of our environment.
Peregrines in Iowa nested primarily on rocky bluffs along the Mississippi River in Allamakee, Clayton, Dubuque, and Clinton counties, plus along cliffs in Linn and Johnson counties. Black Hawk, Boone, and Dallas counties also held nesting peregrines. The last documented Iowa birds nested in 1956, prior to reintroduction.
To restore peregrines, biologists with the Peregrine Fund began “hacking” young falcons in 1974 in eastern states. Hacking involves placing captively produced young falcons in a hack box. The birds are held and fed in the box for several days. Then the box is opened and the birds are free to learn how to fly. Because they cannot capture their own food, they continue to be fed at the box for 6 more weeks. The ultimate goal is to imprint the young on the area (where released) so that when the birds are sexually mature, they come back to the area to nest.
In the Midwest, peregrines were first hacked in southeastern Minnesota in 1982. From 1989-1992, Iowa released 50 peregrines in Cedar Rapids, Des Moines, and Muscatine, as part of the midwestern effort of the Eastern Peregrine Recovery Program. Midwestern releases have been coordinated by Dr. Pat Redig of the Raptor Center, University of Minnesota. Through 2000, over 900 peregrines have been released in the Midwest.
Some peregrines released in the Midwest have returned to the same areas to nest. Others have nested in adjacent states. In 1986, the Midwest had its first peregrine falcon nest in nearly 30 years. By 2000, there were 129 peregrine falcon pairs successfully fledging 243 young. The recovery goal for the Midwest of 40 nesting pairs has been well surpassed.
As a result of releases, Iowa has 5 nesting pairs of peregrines, one pair each in Des Moines, Cedar Rapids, Lansing, Davenport, and the Louisa Generating Station. The Des Moines pair consists of male 93T (from 1990 Cedar Rapids release) and female 13R (from 1991 Kansas City release). This pair has nested each year since 1993 in alcoves atop the American Republic Insurance Building and has fledged (including 3 young in 2001) 19 young. The Cedar Rapids pair consists of male 64T (from 1989 Cedar Rapids release) and female S*/5* (produced by Des Moines pair in 1998). S*/5* replaced female 49R (from 1991 Des Moines release) in 2000. This nest site in a nest box atop the USBank has produced young each year since 1993. Including the 3 young hatched in May 2002, the Cedar Rapids nest has produced 26 (includes one fostered) young. The Lansing pair first nested in 1999, and thanks to efforts by falconer Bob Anderson, is now nesting in a box attached to a cliff. A fourth falcon pair is nesting in a nest box atop the MidAmerican Energy Bldg. in Davenport, and a fifth pair has initiated a nest in 2002 in a nest box on a smokestack at the Louisa Generating Station south of Muscatine. A sixth potential peregrine nest territory has been reported at Mason City by Master Falconer and DNR employee, Lowell Washburn (who previously hacked 25 peregrines from that site).
Because Iowa was not reaching its recovery goal of 5 nesting peregrine pairs by the year 2000, more peregrines were released. An Iowa Peregrine Falcon Recovery Team was formed in 1995 with the goal of establishing a self-sustaining peregrine population nesting at the historic cliff-face eyries of the Mississippi River. From 1995-2000, 104 peregrines were hacked from boxes in Mason City, Bluffton, Effigy Mounds, Dubuque, and the Louisa Generating Station.
In 2000, for the first time in about 40 years, 5 pairs of peregrines were documented nesting on the cliffs of the Mississippi River. Several of these falcons were identified as originating from Iowa releases or nests.
In Iowa, the peregrine project is being spearheaded by the Iowa Department of Natural Resources’ Wildlife Diversity Program. The Wildlife Diversity Program is funded by donations to the Fish and Wildlife Protection Fund Checkoff on the state income tax form. Numerous conservation groups, businesses, schools and individuals have also contributed to this project. In particular, we wish to acknowledge helpful members from the Iowa Falconer's Association, the Raptor Resource Project, Kirkwood Community College, Macbride Raptor Project, US Bank (formerly Firstar Bank) in Cedar Rapids, American Republic Insurance Company in Des Moines, MidAmerican Energy in Davenport and the Louisa Generating Station, and Alliant Energy near Lansing. Our thanks to the many partners and volunteers who are making the peregrine recovery a success!
More Peregrine Falcon Information:
US Fish & Wildlife: American Peregrine Falcon