To date, there are 14 known nesting pairs of peregrine falcons in Iowa and 22 in Illinois. A large percentage of the Iowa population lives in the Quad-City region because the birds favor cliffs and like to be within a mile of a river.
This past spring, the Savanna, Ill., district of the U.S. Fish & Wildlife Service/Upper Mississippi River Natural Wildlife Refuge spearheaded an effort to further increase the population by putting nesting boxes at five new locations.
The boxes were installed at the:
- Former Banner furniture store, Clinton
- Clinton County Courthouse, Clinton
- ADM plant (second location), Clinton
- Exelon Quad-Cities Generating Station, Cordova, Ill.
- Consolidated Barge and Grain, Savanna, Ill.
Of the five, four of the nests went unclaimed. Sometimes, it takes falcons four or five years to claim a box, Rhoni Hartsock of the U.S. Fish & Wildlife Service, said.
But a young falcon laid an egg on a ledge at the ADM site before the box was put in place, so wildlife workers hope that falcon will find the box next season, Hartsock said. And a pair of falcons claimed the Consolidated Grain box within two weeks of it going up and fledged four young, she said.
Nest boxes are spaced a minimum of one mile apart to allow for territorial spacing and are a minimum of 50 feet off the ground. Pea gravel is placed in the box as a nesting medium.
Following are the locations of other Quad-City region nesting boxes and the number of falcons fledged from each this past season.
- Alliant Energy, south Clinton, 3 fledged
- ADM, Clinton (first site), 3 fledged
- MidAmerican Energy building, downtown Davenport, 3 fledged
- Interstate 80 bridge, no reports of activity because of bridge construction
- Centennial Bridge, not currently claimed; the pair that nested there relocated to the MidAmerican Energy building
- Louisa Generating Station, Muscatine, 1 fledged
- Outside the Quad-City region, there is a nesting pair in Ottumwa, a nesting pair in Cedar Rapids and two nesting pairs in Des Moines.
- Interstate 280 bridge, Illinois side, no information available
- A nest box is expected to be installed this fall at 3M in Cordova, Ill.
- Outside the Quad-City region, a large percentage of the Illinois peregrine population is in the Chicago area, nesting on tall buildings.