An aerial survey of bald eagles that state wildlife biologists conducted Jan. 8 along the lower Wisconsin State Riverway found 434 adult and juvenile birds between the Petenwell Flowage and the Mississippi River. This number tops the 2012 survey, which counted 186 eagles, and is the third highest tally recorded since the surveys began in 1992.
The greatest concentration of birds was observed from slightly below the Prairie du Sac dam to the Highway 14 bridge over the Wisconsin River.
“While the count is a useful indicator of eagle abundance, the number swings widely from one year to the next and depends a lot on ice conditions,” said Dan Goltz a Department of Natural Resources wildlife biologist who has taken the survey on this stretch of the river for the past five years. “Fish are a major component of an eagle’s diet and they need open water to fish. Generally, they’ll move as they need to to find good fishing.”
Goltz, who is based out of Boscobel, said in the weeks leading up to last week’s survey he’d been seeing groups of eagles in the uplands around Boscobel, either on perches overlooking smaller streams or on the occasional carrion pile and he wasn’t sure how many they would see actually on the river.
“It started out slow at the northern end of our route but a little downstream of the Prairie du Sac dam it really picked up. It’s hard to predict just where they’ll concentrate other than it will be somewhere near flowing open water,” he said.
DNR aircraft pilot Jeff Oimoen was the pilot for this flight, his third time on this particular assignment.
“I’ve flown all over the United States and nowhere is the scenery better than along the Lower Wisconsin State Riverway,”said Oimoen. “We’re there to count eagles but I see a lot of other wildlife, too. Last week I saw a number of coyotes on the near shore ice, an otter and of course a variety of other birds.”
Asked about any reaction by the eagles to a slow moving aircraft so close to the ground (200-300 feet typically) Oimoen says, “they pay us almost no attention at all. Occasionally coyotes will look up or run but the eagles? They pretty much ignore us and the aircraft.”
Fox River eagles counted
Steve Easterly, DNR wildlife technician in the Fox Cities area, completed his annual aerial survey of the Fox River corridor from Lake Winnebago to Green Bay. His count of 140 adults and immature eagles is down somewhat from previous years. He attributed the drop to there simply being more ice on the water.
“It’s hard to say where the birds are if they are not here,” Easterly said. “They could be as far away as Illinois. It’s all tied to food availability.”
“Overall we’re seeing a healthy eagle population along the Fox River and an increasing number of nests over the past 20 years,” said Easterly, “both are positive indications that the river is attractive to wildlife.”
Eagle watching events
Communities and their partners are finding eagle watching events to be popular winter activities. Several are planned for the coming months. New this year, is an eagle watching event in the Fox Valley on Jan. 26, joining a slate of longer running celebrations and educational programs held along the other rivers: Bald Eagle Watching Days in Prairie du Sac and Sauk City on Jan. 18-19; Eagles on Ice in Alma on Jan. 19; Bald Eagle Appreciation Day in Prairie du Chien on Feb. 23; Bald Eagle Days in Cassville on Jan. 26 and 27, and Eagle Day in Ferryville on March 2.
More information and links to these events, and more information about bald eagles in Wisconsin can be found on DNR’s bald eagle feature page.
Logo courtesy Wisconsin DNR