Despite the temptations of the city, Peregrine falcons living in Chicago remain faithful to their mates. Photo by Mark Medcalf/Shutterstock

CHICAGO, July 15 (UPI) -- Even for birds, the city life comes with extra temptations -- chiefly, a plethora of potential mates. But new research shows, even in the city, Peregrine falcons remain committed to their partners.

"Peregrine falcons that now live in the Chicago region are living in very different conditions than you'd normally see for these birds, so we wondered if the falcons' mating habits had changed too," John Bates, associate curator of birds at the Field Museum in Chicago, said in a news release.


In addition to the higher density of potential mates, urban-dwelling falcons are also tempted by the thousands of comers and goers that migrate through Chicago each year.

"We didn't know what we were going to find," Bates said, "but it turns out that almost all of the mated pairs in the city remain monogamous through the years."

The pesticide DDT, which causes eggshells to become thin and brittle, almost spelled the end for Peregrine falcons in the 1960s, but breeding programs and the banning of DDT have helped falcon populations rebound throughout the Midwest. Now, ninety percent of the breeding pairs in the region use buildings and bridges in the Chicago area to nest.

Field observations and DNA testing helped a team of scientists from the Field Museum and the University of Illinois, Chicago to track the faithfulness of local falcon pairs. Of 35 tested broods, only one revealed a pair of unfaithful parents.

Researchers published their findings in the journal PLOS ONE.

"Whenever you have animals living in habitats that have been influenced by human development, you have to wonder how the animals' life histories will be altered," said Bates. "It's important to do studies like this one to see how birds are adapting to living in human environments, so that we can monitor changes through time."