Peregrine Falcons are a state and federal endangered species. Prior to 1960, there were more than 350 peregrine nests in the eastern United States. By 1964, not
a single peregrine could be found in the eastern U.S., and in 1975, only 39 peregrine pairs remained in the lower 48 states.
DDT pesticides were discovered to be the cause of the decline. The pesticides were sprayed on crops kill harmful insects. The insects were then eated by
small birds. The peregrine preys on the small birds that have ingested the pesticide. With each step up the food chain, the negative effects increased.
The pesticides inhibited the ability of the peregrine (and other birds, like the bald eagle) to produce enough calcium to produce strong eggshells. This caused
vast reproductive failure. Eventually there were no young birds to replace the adult birds, and the population of Peregrine Falcons plummeted. The dangers of
DDT were eventually recognized, and the pesticide was banned from use in the U.S. in 1972. Thus the peregrine was a valuable indicator of the quality of our environment.
Peregrines in Iowa nested primarily along the Mississippi River in Allamakee, Clayton, Dubuque, and Clinton Counties. They also nested along cliffs in Linn, Johnson,
Black Hawk, Boone, and Dallas Counties. The last peregrines before the reintroduction program began were known to have nested in Iowa in 1956.
To restore peregrine populations, biologists with the Peregrine Fund at Cornell University in New York began captive breeding and "hacking" peregrines in 1974.
Hacking involves placing captively-produced young falcons in a large captive "hack" box in known nesting locations. The birds are held and fed in the box for
several days. When the box is opened, the birds are free to learn how to fly. Because they cannot capture their own food, they continue to be fed in the box
for six more weeks. The ultimate goal is to imprint the young on the area where they are released, so that when the birds are sexually mature, they come back
to the area to nest.
In Iowa, peregrines have been hacked in Cedar Rapids, Des Moines, Muscatine, and Mason City. The canyons, sheer walls, and ledges of the buildings in Cedar Rapids and
Des Moines provide artificial cliffs for the falcons. Iowa first released peregrines in 1989 as part of the midwestern effort of the Eastern Peregrine Recovery Program.
Iowa has released 169 peregrines since that time and now has had successful nesting peregrines in several counties each year since 1993.
The goal of Iowa's peregrine recovery program was to establish five nesting pairs by the year 2000. Progress toward reaching this goal has been slow, so a Peregrine
Falcon Recovery Team was formed. The goal of the group is to establish a sustainable peregrine population that requires little or no maintenance or manipulation.
Members of the team include the Iowa Raptor Foundation, Iowa Wildlife Federation, Iowa Falconers Association, McBride Raptor Project U.S., National Park Service,
Ogalala Nation, Iowa Audubon, U.S. Fish and Wildlife Service, Firstar Bank, and Iowa Department of Natural Resources.
Efforts to establish core peregrine populations may be enhanced by additional falcon releases in urban areas in central and eastern Iowa near historic eyries on the
bluffs along the Mississippi River. Nest box placement to entice nesting peregrines will continue in urban areas and on smokestacks of power plants along the
Mississippi River. Fund raising efforts have targeted interested groups. If your school is interested, contact the Wildlife Diversity Program at Wildlife Research
Station, 1436 255th Street, Boone, IA 50036. The peregrine project is supervised by the Iowa Department of Natural Resources' Wildlife Diversity Program. The program
is funded by donations to the Fish and Wildlife Protection Fund Checkoff on the state income tax form.