WATERLOO, Iowa --- The city's newest downtown housing unit is vacant.
But its developers hope the penthouse at the Waterloo Building will attract new tenants to kill and devour a nuisance pigeon flock.
Waterloo Leisure Services' construction crew built a peregrine falcon nest box and installed it atop the building at West Fourth and Commercial streets Feb. 20. Now they're waiting for a pair of falcons --- natural predators for pigeons --- to take up residence.
Mayor Buck Clark championed efforts to attract falcons after someone suggested the birds could help decrease a horde of pigeons that roost on bridges and buildings, leaving droppings that distract from downtown.
"We've had a huge issue with crows and pigeons," Clark said. "The crows come every winter, make a huge mess and eventually leave. But the pigeons we have year round.
"We've tried netting things; we've tried the birth control pill to keep them from reproducing; we've tried putting sticky things or spike sticks on ledges; private groups have tried those things that make noises to scare them away," he said. "Nothing has worked."
Clark contacted The Raptor Resource Project --- a Decorah-based organization that has worked to restore Iowa's peregrine falcon population --- for help. Executive Director Bob Anderson said the Waterloo Building was the best downtown site for the nest box, which he designed 20 years ago.
"I like to call peregrine falcons organic pigeon control," Anderson said. "It won't take care of all the pigeons in town, but it will help."
While downtown Waterloo didn't have buildings as tall as peregrines prefer, the Cedar River was attractive.
"About 90 percent of what urban peregrine falcons eat is pigeons," Anderson said. "And they prefer to catch their prey over water."
It's anybody's guess when a pair of falcons will move into the nest box.
"Sometimes the nest boxes will attract falcons almost right away; sometimes they take years," Anderson said. "But once you do get a pair established, they'll be there forever."
The falcons, which typically migrate to South America, are returning now. Anderson's organization helped re-establish the nest sites in Iowa after peregrine falcons were virtually eradicated from the eastern and central United States during the 1960s, when the pesticide DDT weakened their eggshells.
Clark said he's hoping Waterloo experiences success seen in other communities. Falcon nests near the Quaker Oats plant in Cedar Rapids reportedly led to a dramatic decrease in the pigeon population there, he said.
Waterloo Building owner Gene Leonhart was supportive of the efforts to control the downtown pigeons and allows the box on his roof, Clark said.
Travis Nichols, facilities/project manager for Waterloo Leisure Services, said the city carpenters built two nest boxes based on Anderson's design. The second box remains in storage for now.
Clark noted, "We will wait to see how this goes before another goes up."