Birds wanted: Luring rare falcons to nest in Phoenix Land

UW-Green Bay, peregrine falcons, nesting boxBird enthusiasts at the University of Wisconsin-Green Bay are taking an “if you build it, they will come” approach toward attracting peregrine falcons to nest atop the campus’ tallest building.

Observers could know as early as this month whether peregrines will return to nest, and they’ve constructed a specialized box to make the eight-story Cofrin Library an attractive place to do so. At least two of the falcons, which are endangered in Wisconsin, made the library their temporary home last spring, and the female laid a trio of eggs — but something went awry in mid-May, and the eggs failed to mature.

UW-Green Bay, peregrine falcons, nesting box

Now officials have replaced a nesting tray with a standard nesting box, a larger structure that is more clearly visible atop the eight-story building. Upon recommendation from Greg Septon of Wisconsin Falconwatch, Facilities Management Director Paul Pinkston agreed to provide a specially designed box, and Richter Museum Curator Tom Erdman signed on to monitor for any activity. Facilities’ Jay Rickaby (photo above, left) constructed the box, and with the help of Chris Kieper (photo above, right), on Feb. 20 placed the box on the north side of the library, on the very edge of the roof nearest Theatre Hall.

“We are now in the waiting mode, similar to the Field of Dreams movie — if we build it, will they come?” Erdman said, referring to the famous 1989 baseball flick. “The probability is pretty good that we should see some activity by mid-March. … Chances are probably in the range of 75 to 80 percent that we will have birds, and hopefully success in breeding.”

No one knows what happened to the eggs laid atop the library last year, but Erdman has a couple of theories. It’s possible youth and inexperience got the better of the then-2-year-old female falcon — the birds are banded to identify characteristics, including age — and she made some sort of clumsy mistake with her eggs. A great horned owl or crows could have scared the bird or otherwise caused the eggs to break. It’s also possible that a third bird, a female spotted earlier last year, fought the other female and the eggs were harmed during the altercation.

“We really don’t know,” Erdman said then. “All we know is that the eggs got broken, and it was basically it for that year.”

UW-Green Bay, peregrine falcons, nesting box

Erdman, a bird expert, and his fellow campus avian enthusiasts aren’t alone in hoping the falcons will return. Citizens and scientists nationwide have been fascinated with efforts to restore the peregrine population after their numbers were once decimated by the widespread use of the chemical pesticide DDT.

The birds have made a comeback, and in 2010 a total of 82 young were produced at 27 nesting sites in the state, according to the Wisconsin Falconwatch 2010 season nesting report. Locally, the Wisconsin Public Service Pulliam Power Plant is perhaps the best-known site for hosting falcons, which are monitored via webcam.

The UW-Green Bay campus is ideal for hosting peregrine falcons, Erdman said, due to its proximity to the bay and ample sources of food for the predators. The birds like to nest up high, so the library is a good spot. Or as Field of Dreams fans might paraphrase, “Is this Heaven? No, it’s Cofrin.”