Peregrine falcon nest boxes relocated from Portage Lake Lift Bridge in Houghton CountyAgency: Transportation
Dan Weingarten, MDOT Office of Communications, 906-250-4809
John Pepin, Michigan Department of Natural Resources, 906-250-7260
March 23, 2021 -- Nesting boxes for peregrine falcons on the Portage Lake Lift Bridge have been removed this spring due to the need for bridge repairs.
Peregrine falcons have been nesting on the bridge since 2013, after nest boxes were installed by the Michigan Department of Transportation (MDOT) working with the Michigan Department of Natural Resources (MDNR) in 2012. Repairs to the Lift Bridge service elevators were scheduled for earlier this year but have been delayed because of unavailability of parts. Concerns arose over potential disturbance of the birds while they're nesting.
"In light of upcoming scheduled maintenance work, including a painting project in 2027, we've determined it's best not to put the nest boxes back on the bridge in the near future," said Rob Tervo, manager of MDOT's Ishpeming Transportation Service Center. "Working with the MDNR, we'll re-evaluate the long-term viability of the bridge as an appropriate nesting site going forward."
Despite the removal of the nest boxes, a pair of falcons has been sighted at the bridge again this year. They may be attempting to establish a nest elsewhere on the structure. If this happens, MDOT will attempt to minimize disturbance to the nesting area from bridge operations.
The falcons have had nesting success on the bridge, hatching more than 20 chicks over the years. Copper Country Audubon has maintained a webcam on the nest boxes over the past five years.
Meanwhile, the nest boxes have been relocated to what are hoped to be nesting locations deemed suitable for the falcons. One is on the Michigan Technological University (Michigan Tech) campus on top of the Electrical Energy Resources building. A second was placed atop the Quincy Mine shaft house. Additional locations for nesting boxes are being considered.
"The birds could still use the bridge as a nesting site even with the nest boxes removed," said Brad Johnson, an MDNR wildlife technician at the Baraga Customer Service Center.
On March 11, Johnson, Michigan Tech personnel and members of the Audubon chapter, took a field trip to select potential sites for relocating the nest boxes.
"We did this with the help of the Baraga High School shop class, who built us a new nest box, and members of the Audubon group who designed a nest box base that was favorable to Michigan Tech," Johnson said.
According to the Michigan Natural Features Inventory, peregrine falcons historically nested on cliff faces in Michigan. They have been introduced in several cities "and are faring quite well where they nest on many types of man-made structures and feed on the abundance of small city birds, like rock pigeons."
The inventory has recorded the species in at least eight counties in the Upper Peninsula and 18 counties in the Lower Peninsula.
Visit Copper Country Audubon's website for more information on the webcams.
A peregrine falcon perched on the Portage Lake Lift Bridge, as photographed recently through a spotting scope, is shown. (Joe Youngman photo)