In The Shadow Of Eagles:
An eagle field trip along the Mississippi River
Two decades ago, when Whitewater State Park naturalist David Palmquist started leading bald eagle programs, only one in twenty people he talked to had ever seen an eagle in the wild.
Now, Palmquist and his tours see dozens of eagles in a morning.
On a sunny Saturday afternoon in late March, Palmquist leads a tour bus and eleven cars along Highway 61 in southern Minnesota to spot eagles.
“At this time of year, everybody wants to get outside,” Palmquist says. “People love eagles.”
The eagle tours, a joint effort with the National Eagle Center in Wabasha, attract visitors from around the state and beyond. To Palmquist, the popularity of eagle watching is “a celebration of eagles’ comeback.”
In 1972, the United States banned DDT, the pesticide blamed for decimating the eagle population. A year later, a survey found 115 eagle nests in Minnesota. Palmquist tells tour goers that in 2011, Minnesota’s eagle population has soared to nearly 2,000 nests. Palmquist says changes in the logging industry also helped eagles rebound.
Palmquist leads his tour caravan north from Wabasha to a scenic overlook by Highway 61, where the Chippewa and Mississippi Rivers join. The open water at the confluence attracts eagles, who perch in trees to hunt for fish.
“If they’re perched in trees, boy, they really stand out. Look for the little white dots,” Palmquist says. Several dozen tour goers scan the skies for signs of eagles.
Palmquist notes that eagles seek the easiest food. Gizzard shad are eagles’ first choice, but the big birds will nab any fish that’s been injured or killed going through the locks and dams. Palmquist says eagles also eat dead livestock, injured deer, ducks or geese.
At the second stop, tour goers spot eagles in trees before Palmquist sets up two viewing scopes.
“Look! See the two adults and two immatures? They’re working a thermal,” Palmquist says. Eagles depend on thermal updrafts to carry them so they can save energy. “Birds ride a thermal ridge,” Palmquist says, “This is a bird elevator-- a free ride up.”
Tour goers learn that eagles can fly 35 mph and dive 100 mph and that eagles may be able to see thermals the same way people can see mirages.
The tour drives slowly past two nests at Read’s Landing, a popular eagle watching spot along Highway 61. The last tour stop is south of Wabasha, near Weaver, where tour goers observe a large nest in a roadside tree. The nest is three or four years old, and each year, eagles add to it, so this nest spans more than four feet across. The substantial nest seems proof of eagles’ strength, but Palmquist reminds tour goers that although eagles avoided extinction, they’re still in danger.
“There are eagles this year that will die because of lead fishing tackle.” The veteran naturalist, who’s been at Whitewater State Park for 38 summers, encourages people to ask sporting goods shops to only sell lead-free fishing tackle and deer hunting slugs.
“One BB of lead can kill an eagle. The gut pile left over from a deer kill can end up killing an eagle.”
As tour goers take turns viewing the massive eagle nest, Palmquist notes much of the land along the river here would have been developed if not for the Upper Mississippi Wildlife Refuge.
“This is the major bird highway in the continent, the premier flyway. It gets the most human traffic of any refuge.” Palmquist wants people to understand “that we can still help eagles. It’s our national symbol and we almost lost it. It’s great to celebrate eagles’ comeback, but this never ends.”
Eagles in Minnesota have an eight-foot wingspan. In Alaska, eagles are even bigger.
Eagles lift their tails so their waste spews several feet. That keeps their nests cleaner.
The average eagle produces two eggs. Eggs incubate for 35 days. Usually, only one eaglet survives in a nest.
Young eagles have bigger feathers than adults. Big feathers make flying easier. When the immatures molt, they get smaller feathers.
First-year eagles have dark heads. By their fifth year, eagles are fully mature and have the familiar white head.
Immature eagles are more likely to migrate south in winter. Adult eagles can better survive harsh winters. Migrating eagles return to Minnesota between February and mid-March.
Talon locking is a spring behavior that’s a dramatic show of pair bonding. Two eagles fly close together, then grab each other’s talons. With talons locked, the pair tumbles in the air for a few seconds.