Presentation on bald eagles draws a crowd : News : Oswego Ledger-Sentinel : Hometown Newspaper for Oswego and Montgomery, Illinois
|Presentation on bald eagles draws a crowd |
|Area residents of all ages fill Montgomery Village Hall meeting room |
|by John Etheredge|
A crowd of area residents of all ages filled the village board meeting room at Montgomery Village Hall this past Thursday evening to learn more about the growing number of bald eagles being spotted along the Fox River in the village and surrounding communities.
Margaret Gazdacka, a naturalist and facility supervisor at the Fox Valley Park District's Red Oak Nature Center, told the audience that the bald eagle population continues to grow, but is still well under what it was in the 1700s when the nation's Founding Fathers chose it as the national bird.
Gazdacka said there are currently about 10,000 bald eagles in the 48 contiguous states, another 50,000 in Alaska, and 10,000 in British Columbia.
She added in the 1700s there were as many as 500,000 bald eagles in North America.
"The good news is those numbers are climbing again," Gazdacka said.
Describing herself as an avid "birder," Gazdacka said she and other bird enthusiasts have noted a dramatic increase in the number of bald eagles they've spotted each December in our region as part of the Audubon Society's annual Christmas Bird Count.
"This year we saw a record high in bald eagles in our count," she said, adding, "In 2010 we counted six eagles, this year there were 40. Myself, my team (of bird counters), saw 16 in one day. I've been doing the Christmas Bird Count for 12 years now and up until last year we had seen a total of about 12 eagles. We would get about one on a count, so in one day, one count, we saw 16. It was incredible."
She noted the bald eagle population has made significant gains over the past four decades due, in part, to the banning of the chemical pesticide DDT in 1972.
"At one point there was only about 500 nesting pairs (of bald eagles) left and only 1,000 in the wild," Gazdacka said.
Gazdacka said DDT itself was not lethal to the eagles, but they would ingest it while eating fish, which had consumed mosquitoes and other insects that had been sprayed with the chemical.
Through a process known as biomagnification, Gazdacka said female eagles that consumed the DDT infected fish were rendered sterile or would lay eggs that were too brittle too hatch.
She noted that eagles were also actively hunted in the 1800s and early years of the 20th century, which also contributed to their declining population. However, the legal hunting of bald eagles ended in 1940 when Congress passed the Bald Eagle Protection Act.
The bald eagle was placed on the U.S. Endangered Species List in 1967, but its recovering population prompted Congress to remove it from the list in 2007.
Gazdacka said the bald eagles that area residents are now seeing along the Fox River are migrating southward from Wisconsin and Minnesota. The cold weather this winter has caused more lakes and streams to freeze over in those states, prompting an even larger number of eagles to fly south into Illinois in search of open waterways and fish.
Illinois, she added, currently has the largest winter population of bald eagles outside of Alaska.
She said the Fox River-especially south of the Fox Metro Water Reclamation District plant between Oswego and Montgomery-is an especially attractive spot for the eagles since a large section of the river in that location does not freeze over.
Gazdacka said fish make up between 60 to 90 percent of the bald eagle's diet. They will also eat squirrels and other rodents, and carrion, she noted.
Gazdacka also presented several other facts about bald eagles, including:
•Bald eagles are among the largest birds the world.
•The male bald eagle is smaller than the female.
•The lifespan of a bald eagle can range from 30 to 50 years.
•Bald eagles mate for life.
•Female bald eagles lay between one to three eggs, which take about 35 days to hatch.
Gazdacka said the most difficult time for a newborn bald eagle is the first year. She said if they can survive the first year, they typically can go on to live full lifespans.
•It takes bald eagles four to five years to become adults with the characteristic white head and tail.
•Young eagles stay with their parents even after they have grown to full size, but separate when they migrate.
•Eagles often nest within 100 miles of where they were born.
Responding to a question from the audience, Gazdacka said bald eagles will hunt squirrels and other rodents. She added that bald eagles are strong enough to lift prey up to four pounds, but she believes it is "possible, but highly unlikely" they would hunt small dogs.
Gazdacka encouraged area residents interested in learning more about bald eagles to visit ebird.com. In addition, she extended an invitation to area residents to visit the park district's Red Oak Nature Center, off Ill. Route 25 in North Aurora. She noted the center, which overlooks the east bank of the Fox River, is also a good place to view bald eagles.