Bridges serve as a way for vehicles to get from one place to another, but some also provide nesting sites for endangered bird species.
Such is the case in Michigan, where MLive reports that seven peregrine falcon chicks were born this spring on top of two Upper Peninsula bridges—the Portage Lake Lift Bridge between Houghton and Hancock, and the Sault Ste. Marie International Bridge. Peregrine falcons have been nesting on the bridges for years, Michigan Department of Transportation (MDOT) officials told the news agency.
MDOT installed two nesting boxes at Portage Lake Lift Bridge in 2012. Since that time, a pair of falcons has raised 10 chicks. This year’s chicks were born after the agency took steps to shield the nesting box from $8.4 million in bridge upgrades and maintenance that started in 2014 and ended this spring. Workers put up screens to keep the falcons from seeing them, and tried to keep things quiet near the nesting area.
Nesting boxes were installed at both ends of the Sault Ste. Marie International Bridge. The same pair of peregrine falcon adults has been returning to the nest on the U.S. side every year, but the nest box on the Canadian side has not yet been used. Karl Hansen, a bridge engineer, has counted 20 chicks hatched out of the nest boxes since they were installed, MDOT told the news agency.
This spring, Department of Natural Resources (DNR) workers banded four chicks at the Portage Lake Lift Bridge and three at the Sault Ste. Marie International Bridge. Kristie Sitar, a DNR wildlife biologist, told the news agency that the color-coded bands the agency attaches to the peregrine chicks’ legs will help track their movement, as well as track reproduction and the overall growth of the peregrine population. Biologists have not been able to confirm that birds banded at either bridge have gone on to reproduce.
“There are no records of where fledged birds from the site have gone, but that doesn’t mean they aren’t breeding someplace,” Sitar told the news agency. “Oftentimes, birds aren’t uniquely identified at new sites for a few years.”
The DNR also picked names for the banded chicks. At the International Bridge, workers named the chicks after former colleagues battling cancer—the male chicks were named Jim and Cameron, and the female was named Cheryn. At the Lift Bridge, the two females were named Lynn and Spunky and the two boys were named Edgar and Scottie. The chicks should be ready to fly from their nests in a few weeks.