WATERLOO -- As he chatted about the birders coming in from out of town to peer at his spruce tree on Liberty Avenue a repetitive call pierced the air, and Tom Schilke stopped in midsentence.
"When you hear that sound, start watching," he said.
So Schilke, president of the Prairie Rapids Audubon Society, along with the treasurer of the society, the city arborist and a collection of Schilke's neighbors looked up.
There, a pair of merlins -- a type of falcon -- flew high and fast through the Monday morning sky, hunting their prey -- small birds and mammals -- before that afternoon's storm rumbled through.
Schilke thinks Waterloo might be the only place in the state with nesting merlins. There was a nest of merlins near Hoover Middle School in 2016, he said.Before that there wasn't a recorded merlin nest in Iowa since 1908.
Normally, merlins migrate through Iowa, preferring to breed elsewhere. Now there may be somewhat of a stable population in Waterloo, said Prairie Rapids founding member Francis Moore, noting another nest was sighted near the Subway restaurant on Kimball Avenue this year.
"I'm not so sure" why merlins are hanging around, Moore said. He speculated milder winters in the past four to five years may have something to do with it.
That a pair happened to take up residence in the president of the local bird group's neighborhood, and raise three merlins of their own, seems a happy coincidence.
"It's a real interesting event, because it's really rare for Iowa," Schilke said.
It's also brought Schilke and his neighbors closer together, swapping stories about the merlins and the birdwatchers they're attracting to their normally quiet Waterloo street.
"I think this has given us a chance to meet our neighbors a little bit more," said Art Miranda, who lives nearby.
In the midst of a pandemic and economic upheaval, birds and birdwatching have made a comeback everywhere. But nowhere is that more true than in Waterloo, which for the third year in a row was named a Bird Friendly Community by Bird Friendly Iowa.
Three back-to-back years of that recognition gives it the organization's Sustained Flight status, the first city in Iowa to achieve that.
"Your community's dedication to birds and the habitat they rely on is outstanding," wrote Carole Teator with Bird Friendly Iowa in the June announcement. "The steps that Waterloo has taken to make it possible for people to engage in birding, to reduce threats to birds and to protect bird habitat is exemplary."
Todd Derifield, arborist with the city of Waterloo, hears his fair share of bird stories when he's out and about dealing with the city's trees.
"My kids call me the crazy old bird guy, and I'm not even that crazy," Derifield said. "I think Waterloo birders do rule, though. There's a lot of them, and they're very passionate about it."
Neighbors on Liberty Avenue didn't necessarily realize what having a pair of nesting merlins nearby would mean, including navigating the many people interested in catching a glimpse of the rare birds.
"I basically come home to a lot of people in my driveway," said neighbor Carrie Lalk. "I just put on my blinker and smile, and they move and then they come back."
The merlins tend to use the Miranda family's trees to eat their prey, dropping the inedible bits back to earth. Feathers have floated down onto their plates when they eat dinner outside on nice nights. A tiny bird gizzard even dropped onto Art once.
"Especially now that there's five of them, they'll leave a mess," Emily Miranda said. "But I think the good outweighs the mess."
Lalk doesn't mind the birdwatchers nor their mess, either; rather, she'll be sad to see the merlins finally fly the coop.
"They're just a gorgeous bird and they make a beautiful sound, which I think we'll miss when they leave," she said.