For the Birds Radio Program: Bald Eagle
Bald Eagles On October 27, wind, rain, and snow were fierce enough to close Duluth schools, but not fierce enough to stop eagles or birders. Mike Hendrickson and Peder Svingen saw a California Gull mixing with the usual suspects on the Minnesota side of the Superior Entry until a Bald Eagle chased off the whole crowd of gulls. Raptor counters turned up at Hawk Ridge, too, braving the elements for over four hours to count the three birds that flew over—one Rough-legged Hawk and two Bald Eagles. Me—I didn’t feel like braving the elements, but when I stepped onto my front porch to bring in the mail, a Bald Eagle was passing over, reminding me that the two things I can personally count on in October and November are the migration of Bald Eagles and the U.S. Post Office. Collectively, Bald Eagles are reliable migrants in late autumn, but individually their migration is quite variable and even random. After eagles fledge and no longer need parental subsidies, they spend several years as nomads, wandering wherever they please. Adults are tied to a territory, defending their nest against potential rivals even after their young depart. But during heat waves, adult eagles may wander north for a few weeks. Once weather turns cold, they mosey southward again, but even this is variable. When an individual eagle discovers exceptionally good fishing, it may remain in an area for weeks or months, even in the north. Although eagles seem to prefer fish over anything else, they can easily exploit other prey items, from roadkill to birds caught on the wing. Researchers studying prey remains found at nests along Lake Superior found that 50% of the food brought to nests was fish, while 48% was birds, especially Herring Gulls. Some eagles have learned to hunt cooperatively, with one eagle flushing prey towards another. They don’t mind sharing meals, so this strategy helps both the hunter and the flusher to a good meal. When I pass dead deer along Highway 13 or 53 in Wisconsin, I usually see one to three Bald Eagles dining in a group with several crows or ravens. This time of year I’d much rather see eagles eating deer along the highways than imagine them eating gut piles or wounded deer that escape in the woods after being shot, because lead in shot and bullets is so dangerous. Bald Eagles are functionally illiterate, so it’s understandable why they’d eat meat laced with toxic lead. There’s been a great deal of publicity about how bullets fragment into tiny lead particles that spread far and wide in soft tissue, so now many food shelves refuse venison because of the risk. It seems surprising to me that any hunters who eat their quarry would still use lead ammunition, but I’ve given up trying to understand people. Confusing and complex as their migration patterns are, Bald Eagles are still much easier to fathom than we humans are. Both my sons were born in October. In 1981, I carried my little Joey to the hospital window to see what bird his eyes would gaze upon first. At the time, Bald Eagles were still endangered, but my timing was perfect—a stunning adult winged past our window under a bright blue sky—a most auspicious sign. Four years later, when I held my baby Tommy to the window, an adult Bald Eagle provided a repeat performance. Ben Franklin once served as Postmaster, so you’d think he’d appreciate the reliable migration of this magnificent bird. Franklin preferred the turkey, but really, the only turkey a mother would have a prayer of showing her newborn baby from a hospital in downtown Duluth would be on the dinner tray. Bald Eagles seemed a much finer omen.