Voyageurs National Park biologists found 63 bald eagle nests within the park’s boundary this April while conducting aerial surveys to determine the number and location of nesting pairs.
Adult pairs were observed at 31 of the nests.
Twenty-nine of the 31 breeding pairs were actively involved in incubating, compared to 27 pairs in 2003 and 2004, 28 pairs in 2002 and 2001, 25 pairs in 2000, and 22 pairs in 1999.
Each year since 1992, the park temporarily has closed the land and water areas within a mile of active bald eagle nests to visitor use during their critical nesting periods.
The closures have been based on recommendations of bald eagle researchers from across the U.S. to land management agencies. After the young leave the nest, which usually occurs by the middle of August, these temporarily closed park areas will be re-opened for public use.
This year, specific management recommendations from a two-year research study on the effects of watercraft on bald eagles nesting in Voyageurs (Wildlife Society Bulletin 2002) are being experimentally applied.
Therefore, watercraft users—both motorized and non-motorized—should not approach on the water within 200 metres of bald eagle nesting sites and adjacent land areas.
Boaters are encouraged to not stop on the water within the 200 metres near nesting sites.
This summer, areas around 10 of the park’s 31 nesting sites occupied by breeding pairs are temporarily closed to campers and other human activities. Four of the park’s 225 developed visitor use sites are affected by the temporary closures.
These include the Feedem Island (K39) houseboat site on Lake Kabetogama, Lake, the Skipper Rock Island (R45) and Sand Bay South houseboat sites on Rainy Lake, and the Granite Cliff North (S6) tent site on Sand Point Lake.
Six undeveloped areas that visitors might use on islands and shorelines where active breeding pairs are nesting also are closed to human activity and marked with signs.
Closed areas on Rainy Lake include East Fox Island, Gull Beach Island (north of Diamond Island) and Red Rock Island. On Lake Kabetogama, closed areas include North Wood Duck and Cemetery Islands.
Jug Island is closed on Namakan Lake.
Dr. William Bowerman, a Clemson University research biologist who conducts ongoing studies of bald eagles in Voyageurs, said people play a very important role in protecting nesting eagles and other birds.
“May and June are particularly sensitive periods for nesting eagles,” he noted. “Eagles may still be incubating eggs until late May and if flushed off the nest for too long a period, the eggs will become cold and the embryo can die.
“Or if the adults are continuously threatened, they may abandon their nesting efforts,’’ Dr. Bowerman warned.
“Once hatched, it is during the first four weeks of life that the eaglets are most vulnerable,” he added.
“During this time, eaglets are unable to regulate their body temperatures and need almost constant attention from an adult to protect them from cold winds and rain, or hot sunshine.”
Natural factors also can influence eagle breeding success during critical phases of their reproductive cycle. The Shoepack Lake fire burned the nest and nest tree of an actively nesting pair on an island there late last July.
The young and the adults survived the fire because it occurred late in the breeding cycle.
This season, the birds built a new nest near the island that burned and an adult was observed incubating there. One immature and one adult bird were perched on snags of the island that burned near the old nest site.
Individual eagles differ in temperament and tolerance to human and natural activities at different times in the reproductive cycle. Some are easily displaced by human/eagle interactions early in the cycle and may abandon a nest site while others are more accustomed to close interactions with humans.
Overall, reducing the adverse potential of human/eagle interactions has allowed greater nesting success of eagles throughout the United States.
“Our management goal is to help ensure the continued reproductive success and recovery of this population of bald eagles, our nation’s symbol,” said VNP Superintendent Barbara West.
Fort Frances Times
Local News from Across the Rainy River District
