What's Happening on the Hudson River in December
The calendar says that winter arrives in December, but it doesn't account for year to year weather variation. December usually brings the first significant snowfall to the lower regions of the Hudson Valley, the first ice on the river and its tributaries, the first flurry of activity at our bird feeders, and the arrival of the first wintering bald eagles from Canada. Other years, the days are mild and autumn-like, and the river stays warm - high 40s, low 50s - throughout the month. If there is no snow or ice, songbirds are fickle about feeder offerings. In the High Peaks area of Essex County, ice should cover ponds and lakes while snow fills the woods this month. Ice fishing, cross-county skiing, and snowshoeing will begin even as residents of the lower Hudson, 300 miles south, may feel a warm southerly breeze on their faces while out fishing for hake and tomcod.
Even in a warm year, by December's end real winter will set in. Falling water temperatures speed straggling young-of-the-year shad, striped bass, and river herring towards the brackish water of the lower Hudson, but most of the autumn migration is over. Acres of shad and herring have left their estuarine nursery, summoned to the sea to join their parent stocks. Meanwhile, juvenile blue crabs have burrowed into the sandy bottoms of the rivers shallows for the winter. This is the northern limit of their range, and depending on the winter's harshness, and luck, they'll avoid being crushed under tons of shelf ice.
Creeping out from shore, the ice grows each night, and survives further into each day as the sun's strength wanes. The ice forming on marshes, small ponds, and rivers sends waterfowl south or drives them to larger water bodies that stay ice free longer.
December is the month when waterfowl migration along the Hudson peaks. Rafts of snow geese and Canada geese, numbering in the thousands, can be seen on the upper Hudson below Fort Edward. Unless real winter cold and ice sets in, they will be in no hurry to leave. Similar rafts of wild geese may be found on the Hudson's tidewater from Troy to Staten Island, usually far offshore and barely within binocular range. There will also be rafts of diving ducks such as canvasbacks and lesser scaup, with smaller numbers of ruddy ducks, common mergansers, goldeneyes, and buffleheads among them. New York Harbor's Upper Bay will host rafts of scaup and oldsquaw, flocks of brant (a small goose), a scattering of red-breasted mergansers, and pairs of common loons in their winter plumage.
The arrival and density of wintering bald eagles correlates to the icing up of the river and growing numbers of wintering waterfowl. As their Canadian home waters skim over with ice, eagles have little choice but to move south. They need consistently open water to hunt fish and waterfowl. Mild winters provide these eagles with many options. Some fly south only to the St. Lawrence River, the upper Hudson, and the Battenkill and Hoosic Rivers in Washington County. However, usually by late December, winter will drive eagles and waterfowl south to the Hudson River Estuary. As the tributaries, tidal marshes, and upper reaches of the estuary ice over, these birds will be increasingly concentrated into the lower Hudson River. For more information on Hudson River bald eagles, visit the DEC's Bald Eagles of the Hudson River webpage or the Journey North webpage (see link at bottom of page).
While out spotting eagles on ice floes this winter, keep a sharp lookout for other animals. It is not rare to see a harbor seal hauled out on an ice floe sleeping off a meal of white perch or Atlantic tomcod. On a couple of occasions, we have even seen eagles and seals sharing an ice floe, albeit a large ice floe! You may also see coyotes, fox, and white-tailed deer using the ice to cross coves and tributaries and reach islands. After a nor'easter, accidentals like gannets and shearwaters may be seen, blown inshore from the open ocean. As winter deepens, look for snowy owls. They may be seen along the flat, open coasts at Jamaica Bay and Sandy Hook. A few are seen most winters in both Ulster and Westchester Counties.
A great way to celebrate the season outdoors is to participate in a Christmas Bird Count. Many Hudson Valley birding organizations and interpretive centers send out teams of birders to document the variety of species and the numbers of each present at this time of year. Depending on the weather, they might find lingering warblers that should have gone south long ago, or rare raptors from the far north, driven south by lack of prey on the tundra. Severe storms can blow migrants off course, such as open-ocean birds or even those from as far away as the western US or Europe! The sponsoring organizations are always looking for volunteer birders to help them observe and count. Treat yourself to a brisk day along the river in a spirit of adventure and discovery.
On December 21, we will welcome winter with the solstice. From this point onward, the earth will begin to slowly tilt its northern hemisphere back towards the sun, giving us a few extra minutes of sunlight each day. But before we welcome spring, we must get through our coldest weeks of winter, from late December through early January. If you love the crunch of winter snow under your boots and the bracing feel of winter winds on your face, this will be your time. If these things do not appeal to you, fill the bird feeder outside your window and enjoy the winter season indoors, with a hot drink and a good book.