Bald eagles experiencing a baby boom in central Illinois
An established pair of bald eagles appears to have a strong start on raising a family for the third year along the Sangamon River north of Springfield — and they’re not the only ones.
A helicopter trip from Springfield to near Havana along the Sangamon River and its tributaries turned up five eagle nests — four with an adult eagle sitting tight on the nest. A fifth active nest has been established on an island in Lake Springfield.
“I am just shocked they are this dense and that there are so many in this area,” says John Wilker, natural areas program manager for the Illinois Department of Natural Resources. Wilker flew along with Illinois Department of Transportation helicopter pilot Steve Young on Wednesday.
“What are they, eight or 10 miles apart?” he asks. “So, you think there might be more than 100 nests in the state?”
In the early 1980s, Illinois had exactly two bald eagle nests. Now the estimate is somewhere north of 100. That number is fluid, because nests are destroyed by storms or collapse under their own weight and may be rebuilt elsewhere.
Wilker was flying over natural areas in Sangamon County that are being considered for listing on the state’s Natural Areas Inventory — first developed in the 1970s and currently being updated.
He also was checking on reports of eagle nests reported by the public. The Salt Creek eagle nest is a new discovery, as was a nest with no eagle present along the Sangamon just south of the confluence with Salt Creek.
Wednesday’s flight was surprising because eagles are spreading out in the Illinois River valley and settling on rivers such as the Sangamon that feed the Illinois.
“They are nesting along tributaries and tributaries of tributaries,” Wilker says of the nest on Salt Creek.
Young, who flies missions ranging from homeland security to nighttime deer surveys, has honed his eagle eyes, often spotting nests and eagles before anyone else in the helicopter. “There’s the nest,” he says moments after lifting off from the airport. “I see an eagle’s head.”
Young and a technician videotaped the eagles using the helicopter’s built-in camera during the eagle’s first summer on the Sangamon, providing videotaped proof of young in the nest.
Some young eagles build a nest but aren’t serious about starting a family right away.
Wilker says young pairs will attempt to build a nest as a pair-bonding exercise.
“They’ll build a play nest and then abandon it,” says. “They still may be a little immature.”
H. David Bohlen, assistant curator of zoology at the Illinois State Museum, says he has had trouble seeing the second eagle at Lake Springfield.
Bohlen has studied birds in Sangamon County and the effects of urbanization on the number and types of birds present.
“I see the eagle sitting there every morning, but I never see the one on the nest,” he says. “It must be hunkered down low.”
Otherwise, Bohlen agrees the pair may be too young to be serious about starting a family.
“Maybe they’ve just built a nest but they don’t really know what to do yet,” he says. “I think they do that sometimes.”
One of the eagles was on the nest Wednesday, and flew off briefly when the helicopter circled the island. No eggs were seen, but the view into the nest was not perfectly clear.
About a quarter mile west of the Illinois 29 bridge north of Abraham Lincoln Capital Airport, eagles are sitting on a nest for the third year. It was the first recorded successful nesting in Sangamon County.
“I was flying over there (March 9), and there was one sitting on the nest and she is really hunkered down tight,” Young says. “When we fly by, a lot of times they will sit up and look at you, but she laid down tight, so she is definitely sitting on something.”
Young was assessing tornado damage when he decided to check in on the local eagle family.
“I don’t like to go by a lot because I don’t like to bother them, but I happened to be coming in from that direction,” he says. “It’s pretty obvious there is something there, but I don’t know if it is an egg or chick.”
City Water Light and Power employees have noticed a pair of adult bald eagles on a nest in an island at Lake Springfield.
CWLP spokeswoman Amber Sabin says the utility will evaluate the situation to see if any action is necessary to protect the eagles.
“We will make lake security aware,” she says. “We don’t want to cause more of a problem by alerting boaters to where it would become a tourist thing.”
Once the trees leaf out in a few weeks, the nest at Lake Springfield likely will be difficult to see at all.
A nest is visible from the Illinois 97 bridge where it crosses the Sangamon River near Havana. An eagle was on the nest Wednesday. Bohlen has seen a fourth nest near Buckhart, and that one was active, too.
Young says eagle nests — once rare — are becoming more commonplace.
“It’s funny flying around the state — you just see more nests around,” he says. “It’s really a success story.
“I’m glad to see the (eagles north of the airport) nesting here still.”
Chris Young can be reached at (217) 788-1528 firstname.lastname@example.org.
Area eagle nests:
1. Lake Springfield
2. Near Buckhart
3. Along the Sangamon River off Illinois 29 north of the Abraham Lincoln Capital Airport
4. Unoccupied nest just south of confluence of the Sangamon River and Salt Creek
5. On Salt Creek east of confluence with the Sangamon River
6. On Sangamon River just off Illinois 97 between Oakford and Kilbourne