The fog has not lifted yet off the Susquehanna, and already the trees along the far shore are full of dark shapes.<\/p>\n
Below a concrete wall nearly a mile long, the water churns white.<\/p>\n
Something flashes silver just under the surface, belly up, stunned.<\/p>\n
A shape drops out of a bare tree before the ripple even settles.<\/p>\n
On the best mornings of the cold months<\/strong> there are hundreds of eagles here at once.<\/p>\n What happens here has very little to do with luck.<\/p>\n Conowingo Hydroelectric Station, on the lower Susquehanna between Cecil and Harford counties in Maryland, runs eleven turbines that pull river water down through steel intakes to spin generators. The dam was built with eleven turbine sites, seven installed at first and four higher capacity units<\/strong> added later, raising output from 252 to 548 megawatts<\/strong>.<\/p>\n Fish riding that water do not all come out the other side unharmed. The intakes draw water and fish through the dam, often stunning or killing them and depositing them downstream where they are easy to catch. Shad, herring and other species arrive below the powerhouse limp rather than swimming free.<\/p>\n Others are stopped rather than stunned<\/strong>. Migrating fish find themselves blocked from moving upriver and mill around the tailrace, and that steady supply of easy, visible food is the reason eagles bother showing up at all.<\/p>\n Because eagles hunt by sight, a fish floating belly up asks almost nothing of them. Birds perched in trees and on towers and rocks can pick out a pale belly from roughly a mile and a half<\/strong> away.<\/p>\n A second mechanism matters just as much as the fish, and it has nothing to do with the blades. The Susquehanna below the dam rarely freezes, because of the rapid downstream current<\/strong>, so open water stays available here after ponds and shallows farther north have locked up.<\/p>\n When those northern waters do freeze, eagles relocate rather than go hungry. Roughly 75 to 100 eagles keep nests along the Susquehanna and will fly up to about 25 miles to reach<\/strong> the dam.<\/p>\n Those resident birds are joined by migrants. The peak numbers arrive in fall and winter, when lakes and rivers freeze farther north in New York state and the Ohio Valley, and timing matters more than most visitors realize.<\/p>\n So late fall through January brings the highest concentrations<\/strong>. Arrive on the wrong week and the riverbank can look nearly empty.<\/p>\n Most casual accounts describe the spectacle in the low hundreds, and that figure is not wrong so much as conservative. Around 350 eagles<\/strong><\/a> have been counted on top days, which puts Conowingo among the largest winter gatherings of bald eagles on the East Coast.<\/p>\n Ordinary days are smaller and still crowded. A naturalist group visiting in December saw at least 100 eagles without using<\/strong> binoculars, and a professional birder counted 154 the day before.<\/p>\n Even so, photographers who return year after year describe the same scrambling over the same fish. The founder of a widely followed Conowingo eagle page has said it is not unusual to see a fish change hands two, three or four times at the dam, with birds robbing each other in the air<\/strong> rather than diving for their own.<\/p>\n Which means the gathering functions less like a handful of individual hunters and more like a crowded fishing dock.<\/p>\n Moving fish upstream past the dam is a license obligation as well as a restoration goal. The operator has run fish collection facilities at the Conowingo project since 1972, beginning<\/strong> with a west fish lift<\/a> and adding a much larger east lift that began operating in 1991.<\/p>\n The lifts do not simply let fish swim through. Gates and channels attract fish into a hopper that is lifted over a sorting tank, where biologists pick out shad and river herring and truck them upstream in portable tanks. By 2001, nearly 200,000 adult shad<\/strong> were counted at the Conowingo lifts.<\/p>\n Elsewhere, engineers have tried redesigning the turbine itself so fish pass through alive, the way a reshaped hydropower unit at a small Maine mill dam let river herring swim clear<\/a> of the blades. A similar idea has been tested with eels sent through a compact canal turbine<\/a>.<\/p>\n None of this means the eagle numbers at Conowingo keep climbing without end. Counts depend heavily on how hard the winter bites farther north, and a mild season upstate<\/strong> keeps many migrants from ever traveling this far south.<\/p>\n So visitors who show up expecting a guaranteed crowd sometimes find a calmer river with a few dozen eagles scattered in the trees instead. Even so, the basic arrangement has held for decades, and nesting around the dam has increased sharply since 2010<\/strong>.<\/p>\n A concrete wall nearly a mile long, built to turn a river into electricity, has become one of the most reliable eagle viewing sites<\/strong> on the East Coast.<\/p>\n The birds never read a press release about it. They come back each winter because the fish still arrive stunned and the water still refuses to freeze.<\/p>\n","protected":false},"excerpt":{"rendered":" The fog has not lifted yet off the Susquehanna, and already the trees along the far shore are full of dark shapes. Below a concrete wall nearly a mile long, the water churns white. Something flashes silver just under the surface, belly up, stunned. A shape drops out of a bare tree before the ripple … Read more<\/a><\/p>\n","protected":false},"author":28,"featured_media":45200,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rank_math_focus_keyword":"about 350 bald","rank_math_title":"About 350 bald eagles crowd the churning water below a Maryland dam on the coldest winter mornings, drawn by fog and stunned fish","rank_math_description":"Below a Maryland dam, hundreds of bald eagles gather each winter to feast on stunned fish and open water that never freezes.","footnotes":""},"categories":[8],"tags":[],"class_list":["post-45185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-energy"],"_links":{"self":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/45185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/users\/28"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/comments?post=45185"}],"version-history":[{"count":1,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/45185\/revisions"}],"predecessor-version":[{"id":45201,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/posts\/45185\/revisions\/45201"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media\/45200"}],"wp:attachment":[{"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/media?parent=45185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/categories?post=45185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ecoportal.net\/en\/wp-json\/wp\/v2\/tags?post=45185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Eleven turbines hand the birds an easy meal<\/h2>\n
Open water that refuses to freeze draws hundreds in<\/h2>\n
Counts reach 350 eagles on the best winter days<\/h2>\n
Fish lifts have carried shad upstream since 1972<\/h2>\n
A mild winter upstate can thin the crowd fast<\/h2>\n