Bird of the Month: The Bald Eagles of Conowingo Dam

by Mike Strzelecki*

About 90 minutes south of Boyertown, the Susquehanna River - the third oldest river in the world - spills into the Chesapeake Bay. Just upstream of this confluence is the colossal Conowingo Dam, one of the largest non-federal dams in the United States. The dam forms the Conowingo Reservoir, and is a haven for boaters and fishermen. But in winter, birders are the recreationists that are most attracted to Conowingo Dam. The reason: it is one of the largest gathering spots in the world for bald eagles.

A handful of eagles are “residents” of the Conowingo Dam area, meaning that they live there year-round. But the visiting eagles begin arriving in late fall, and proliferate the river area immediately downstream from the dam. Some may stay a few weeks before moving on, others may stay months. But at any point in winter months, the number of bald eagles inhabiting the dam area usually runs in the 100s. At its peak, 500 eagles can be observed there in a day. By spring thaw, most are gone, heading back to their breeding grounds.

What attracts bald eagles to this site? There are several factors drawing them here. Eagles feast primarily on live fish. The Susquehanna River below the dam rarely freezes, due to the rapid downstream current. As such, it’s one of the northernmost areas in the eastern United States where eagles can catch live fish all winter long while other water sources are frozen. Further, the Conowingo Dam has 11 turbines, usually active. As water passes through the turbines, so do fish that get sucked into the intake. They subsequently get chopped up and spit out into the tailrace pool, providing the eagles with a quick and easy sushi meal.

Scores of birders and photographers come to Conowingo during the winter months each day to observe eagles fishing and fighting over their catch, and to get images of such a beautiful event. The observation area is called Fisherman’s Park. It has about 100 parking spots, but on winter weekends, these spots fill quickly and satellite parking is available with a shuttle bus bringing the overflow to the observation area. It is not unusual to see a line of hundreds of very expensive cameras lined up on the banks of the river during winter weekends.

I recently visited the Conowingo Dam with a photographer friend to try to get images of the eagles flying, fishing, and fighting. We chose a weekday to avoid the crowds and arrived well before sun-up to procure a spot in the prime observation area. Alas, on this particular day, we were greeted with a large fog bank that clung tightly to the river most of our time there, but would occasionally lift and thin-out, providing some opportunities for photography. Here are a few images from the day.

On this particular day, during the periods of low fog, we could see the proliferation of eagles blanketing the area, and estimated their number to be about 300. Scores perched in the riverbank trees behind us, about 75 clung to a pair of electric towers on an island near our set-up, and no less than 100 perched on a rock bed that cut into the river. Bald eagles do not get their trademark white head and tail until they are about three or four years old. Juvenile bald eagles are brown with some white mottling. On this day, we figured that half the bald eagles we saw were adults and half juvenile.

Here are two shots of adult bald eagles

Here are two shots of juvenile bald eagles.

Here, through the fog, is a shot of eagles perched in trees near us, waiting for the proper fishing visibility. We visited the dam during the shad run, where tens of thousands of shad migrate up the dam before meeting concrete and becoming confused (a fish elevator eventually lifts many of these shads above the dam into Conowingo Reservoir). Shad was the meal of choice for eagles during our observation period.

The actual catching of the fish was enjoyable to observe but challenging to photograph, since it happens so quickly and involves quick, darting movements. We noticed the fishing expertise of the adult eagles. They would spy a shad lying near the water surface, launch from the tree, perform a quick swoop, and grab the unwary shad with its talons in a very fierce and resolute manner. From there, the eagles would take their shad to an eating area, usually a thick tree branch.

Fishing did not come as easy to the juvenile eagles. Their flight patterns were not as smooth, they would sometimes whiff trying to catch the fish, and they would spend a lot of time circling the river, learning how to spot the fish. They brought some comic relief to our long day on the riverbank.

Somewhere along its evolutionary track, the bald eagle figured out that it is sometimes easier to steal an already caught fish from another eagle rather than catch one itself. Often, whenever we would see an eagle catch a fish from the Susquehanna waters, that eagle would be tailed and attacked by other eagles trying to steal its lunch. These battles would involve lots of dive-bombing and some talon-to-talon fighting. Some fights would involve over a dozen eagles. Though tough to capture, here are a few shots of eagles fighting over an already caught fish.

On rare occasions, the eagle who snatched the fish from the river’s grasp will simply glide off unimpeded and enjoy its meal on a secluded tree.

Conowingo dam also provides other treats for visitors who show patience. Besides the eagles, the area is rife with hundreds of double-crested cormorants and various gulls - all vying for the same shad. Flitting in the trees around me were ruby-crowned kinglets and Carolina chickadees. Woodpeckers called from the woodlands behind me. For serious birders, a visit to Conowingo Dam during eagle season is a must-do. But even casual birders and naturalists can fully appreciate a display put on by Mother Nature that can only be described as World Class.

* Mike Strzelecki is a freelance travel and outdoor writer, and 1981 graduate of Boyertown Area Senior High School. He writes from his house in Baltimore, Maryland. In his spare time, he joins his wife on adventures around the country observing and photographing birds.

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