Shelby TownshipMarch 25, 2014
Experts believe Stony Creek eagles produced egg or eggs
By Sarah Wojcik
C & G Staff Writer
SHELBY TOWNSHIP — Despite fears that excessively cold temperatures would keep the bald eagle couple that nests in Stony Creek Metropark from reproducing, it appears they successfully produced an egg or eggs.
The Stony Creek Metropark Nature Center’s volunteer bird expert and eagle monitor, Ruth Glass, announced the news after a trek to the nest March 13 revealed behavior indicative of incubation.
Glass said it would be impossible to tell how many eggs the couple produced until about May, when birders could count heads, but she said she hoped that number is two. The eagle couple produced one egg on March 9 last year, which she said is normal of first-time mates.
“Eagles normally lay two to three eggs; two is by far the most common number,” Glass said. “I don’t want to see them have three, because baby eagles fight their siblings and are likely to kill their siblings.”
She added that, with the lowering of lake levels last year for a dam repair, much of the eagles’ regular food supply died off. It would be difficult to keep three eaglets fed.
Glass estimated the egg(s) would hatch on April 17, since she said eagle eggs hatch exactly 35 days, or five weeks, after being laid.
Birders witnessed the eagles mating at least twice — the first time on Feb. 23 — and, as a result, established a rotation of eagle monitors or “babysitters.” On Feb. 26, as a precaution against the cold, concerned birders also dropped a hay bale nearby for extra nest insulation.
Glass said eagles produce four to five days after copulation, so the group had to be vigilant. In her determination, she weathered several miles of blizzard conditions and deep snow to observe the nest, which is located along the Inwood Trails, north of the nature center.
“My guess was nobody had been there, since there were no reports in a couple of days. No matter how bad the trails were, I felt I needed to get out there,” she said.
Despite having snowshoes and skis, Glass decided to go on foot in order to carry her large binoculars, spotting scope and tripod.
“I just walked as much as I could in the bitter cold, and as soon as I started breathing hard, I’d take a break. It took forever to get out there. But I’m so glad, because it was worth it,” Glass said.
She said that when she approached the nest, the couple was sharing a rabbit. Then the male flew to a nearby perch and the female, she said, hunkered down very slowly, carefully spread her legs in the nest and balled her talons into fists.
“It sure looked like there’s an egg. I stayed out there over a half hour just to check that nobody was getting up,” Glass said. “She’s been eating voraciously the past couple of weeks.”
While both eagles take turns incubating the egg, Glass said she expected the female to do most of the job. She said female bald eagles’ blood vessels are located closer to their skin so they are able to produce more heat, and the National Weather Service forecasted a cold spring.
She added that birders would likely see less of the male eagle in the park, since he would have to travel farther to find food.
Jeff Steinmetz and his wife, Jennifer Andersen, of Sterling Heights, were among those on incubation watch. The couple began getting involved in Glass’ monthly bird walks in July on a friend’s recommendation, he said.
“The first time we went on a walk to see the eagles in July was amazing. The (juvenile eagle) couldn’t fly yet, but still it was almost a full-grown eagle with a 5-foot wingspan,” Steinmetz said.
He added that he is hopeful to watch the eaglet-rearing process from the beginning this year.
“Being able to see eagles regularly 20 minutes from our house is pretty cool. We enjoy it quite a bit, and we’ve definitely been spreading the word,” he said.
Nesting season will last until September, and the eastern half of the wetland loop trail has been closed since Feb. 26.
The United States Fish and Wildlife Service maintains that 220 yards, or an eighth of a mile, is the absolute closest distance permissible to a bald eagle nest site. Encroachment or disturbance violations typically carry a $5,000 fine.
The USFWS and Michigan Department of Natural Resources recommend a viewing distance of 440 yards, or a quarter of a mile.
Due to human encroachment, particularly by photographers, the eagles abandoned their original nest site in the main part of the park last year, Glass said.