Bald eagles, ospreys have contrasting styles as predators


Not long after I wrote a column on ospreys, I spotted a pair of mature bald eagles on Northeastern’s campus. I’ve never seen any at school before, but I see them occasionally around Elizabeth city and in surrounding counties.

Bald eagles are a bit larger than ospreys. They eat a greater array of food, too. These powerful raptors catch fish, their favorite food, but they also can take down larger prey. They usually don’t, because that’s too much work.

Eagles don’t like to expend more energy than necessary. Like most predators, they don’t usually take unnecessary chances either. Taking on larger prey like dogs and cats could get them injured. Permanent injury to a predator ultimately means death. Fish are safer.

Ospreys usually make a steep dive for their prey. Sometimes they travel as deep as four or five feet into the water, while eagles catch fish near the surface. These two efficient predators have contrasting styles, and I enjoy watching both.

Eagles fly at a shallow angle when approaching the water. They don’t decelerate much. An adult bald eagle can snatch a three-pound smallmouth and keep right on flying. I’ve seen it.

Large mature bald eagle perched in a white pine in downeast Maine

Eagles also like to view their hunting spots from high perches, rather than fly or glide around scoping out food like turkey vultures do. Eagles also don’t limit themselves to living prey. They are opportunistic and will steal food from other predators.

I saw one eating from a deer carcass once. They will also attempt to pilfer food from other eagles in midair. Bald eagles also like to follow ospreys around and steal from them. Since they are about three times the size of ospreys, the ospreys rarely challenge them.

They also hunt in pairs sometimes. A few years ago, I observed a pair of eagles harvest the offspring from a pair of loons. The communication and coordination were incredible. The loons tried desperately to save their young, but they were no match for the eagles.

We ware all familiar with the appearance of adult bald eagles, but many people don’t recognize what younger ones look like. Eagles don’t develop the classic white head and tail feathers until they reach sexual maturity at four-years-old. Sometimes they don’t mature until they are five.

Immature eagles start out mostly dark colored with dark beaks. Their body colored becomes flecked with white until their fourth year. The beak changes to a bright yellow color by year four. During this time eyes also change from dark colored to bright yellow.

Female bald eagles are slightly larger than males. Both work to build nests, which are often over ten feet deep and eight feet across. Eagles, like ospreys usually fortify their nests every year, so after several seasons they are spectacular. No other bird in North America builds nests as large as bald eagles do.

Alaska is the state with by far the highest population of bald eagles. Cold weather is not the reason, as there is a significant population in Florida. Every state except Hawaii now has growing populations of bald eagles.

 

Ted Manzer teaches agriculture at Northeastern High School.

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About tedmanzer

I grew up in Old Town Maine and got a B.S. at the University of Maine in Plant Sciences/ minor in Botany. From there I moved to West Virginia and earned a M.S. in Agronomy at WVU. I also met my wife there. She grew up in rural WV as the daughter of tenant farmers who raised cattle and hogs. Their lifestyle at times was one of subsistence and I learned a lot from them. I've always been a foraging buff, but combining my formal botanical knowledge with their practical 'Foxfire-type' background opened up my eyes a little more. I now teach agriculture to high school students at Northeastern High School in Elizabeth City, NC. My wife teaches with me and we make a great team. I also write a weekly nature/foraging column for the local paper (dailyadvance.com). I also have written several Christian nature/adventure novels that I plan to publish eventually. One is a five book family saga I call the 'Forgotten Virtues' series. In the first book, Never Alone, a young boy comes of age after his father dies in a plane crash, and he has to make it alone. Never Alone is now available in paperback, Kindle and Nook. The second book, Strange Courage, takes Carl from his High School graduation to his recovery from a nasty divorce. The third book, Second Chances, takes Carl from his ex-wife's death and the custody of his son to his heroic death at age 59. The fourth book, Promises Kept, depicts how his grandchildren react and adjust to his death. In the final book, Grandfather's Way, his youngest and most timid granddaughter emerges from the shadow of her overachieving family and accomplishes more in four months than most do in a lifetime. I use many foraging references with a lot of the plants I profile in these articles in those books.
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