Since I was already near Harrisburg for a family Christmas celebration, I took the opportunity last Wednesday to visit the lower Susquehanna River with Scott Gregg and his daughter Karena, birding friends from Beaver Falls. Our goal was to see bald eagles.
Our main stop was Conowingo, a hydro-electric dam in Maryland and the last dam before Chesapeake Bay. The river was so high that the floodgates were open and sirens were wailing to warn boaters of the flood and turbulence. Spray rose from the dam’s waterfall and hundreds of gulls wheeled through the mist. Black vultures hunched on the dam and in nearby trees. Great-blue herons waited out the flood on a rocky downstream island.
We saw more than a dozen bald eagles but it was hard to count in the misty air. Some perched on the power towers, some circled above the electric lines. There were more immature eagles than adults. The immatures are mottled brown like a huge hawk without the white head and tail until their fourth or fifth year. Chuck Tague’s picture shows an adult eagle in Florida (that's why the sky is blue!).
Bald eagles are in the genus of sea eagles. They always live near water and eat mostly fish. During the breeding season they claim a territory and keep other eagles away but in winter they congregate in large numbers where there is open water and lots of fish. The dams along the lower Susquehanna are just such a place.
Apparently the fishing was easy at Conowingo. With the river rushing through the floodgates, the fish were taking a beating. No wonder we saw so many gulls, black vultures ... and bald eagles.