By Bill Rhoades | Conservancy of Southwest Florida volunteer
As a volunteer at the Conservancy of Southwest Florida’s Dalton Discovery Center, I have the opportunity to learn facts about our resident wildlife that I never knew — but thought I did.
Take, for example, our adult bald eagle (Haliaeetus leucocephalus). Definitely not bald, he sports a head covered in white feathers, with piercing eyes and a yellow, powerful beak. While it is hard to know a bald eagle’s sex by looking at it (adult bald eagles of both sexes look identical), females average about 25% larger than males. Ours perches high in its large outdoor cage, its size, white head and tail making it look as majestic as the symbol of our country should.
He was transferred to the Conservancy’s Von Arx Wildlife Hospital in 2007 after he had collided with a power line, damaging his left wing. He is not able to fly perfectly and cannot be released. Adult bald eagles are considered the largest North American ‘true’ raptor, although golden eagles can be practically as large, and the California condor, a type of vulture, is larger.
Bald eagles may attain body lengths of three feet, wingspans of seven feet and weigh up to 10 pounds. In the wild they live about 20–25 years; in captivity they may live as long as 40. Bald eagles range from Canada to northern Mexico, and once were on the verge of extinction, due in part to the use of persistent, potent insecticides like DDT. This long-lasting chemical concentrates in the food chain, until top predators, like the bald eagle, have levels that cause their egg shells to become brittle and crush as the adult incubates them.
Through environmental efforts and legislation, the bald eagle has regained its numbers, and it is no longer on the endangered or threatened species lists.
Generally living near open bodies of water and preying on fish, bald eagles will also catch and eat small mammals and water birds. But they have a habit of using their massive size to ‘bully’ other smaller predators in order to steal their catch, rather than hunt for themselves.
I had long believed that Benjamin Franklin, when the new government was naming the bald eagle as our national symbol, objected and instead suggested the wild turkey, a more ‘wily’ and clever bird. It seems there is no historical evidence of that, but Franklin did write to his daughter to express his displeasure at the selection, as he felt it was an animal of “bad moral character”, that does not “get his living honestly.”
And about that name — I had thought that the stark white contrast of the head made people think of a man’s bald head — but, not true. It is from the word ‘piebald’, which means ‘having white spots against a dark background’. Not especially creative, perhaps, but certainly accurate.
Visit the Conservancy, meet the animals and staff, and learn more interesting facts about the wildlife in and around our area.