Hudson River bald eagles defend their turf

(Photo by Steve Chorvas)

(Photo by Steve Chorvas)

Binoculars are standard gear for birdwatchers and ship-spotters. They are worth their weight on a hike, especially to the Lighthouse where there is plenty to see, and especially during the spring thaw when so much is happening along the river corridor. With a bit of magnification, the obscure dark silhouette in a distant treetop becomes a bald eagle. The indistinct black-and-white diving bird swimming along the creek appears as a loon in its breeding plumage. In a raft of waterfowl, the ringed-neck duck can be distinguished from the canvasback.

When pointed at an anonymous boat, a pair of binoculars makes legible the name emblazoned across the stern. Tugs and barges read like genealogies: Reinauers, McAllisters, Polings and Culters. On a cold day, reading the foreign port off the stern of a cargo ship or tanker can inspire a wish that the vessel was delivering a cargo of tropical warmth from places like the Bahamas, Panama or Barbados.

For anyone with a pair of binoculars, the main attraction at the Lighthouse seems to be the resident breeding pair of bald eagles. The eagles stir quite a bit of interest from visitors, who see them fishing and foraging in the bays and coves around the mouth of the Esopus Creek. They nest across the river and frequent treetops on this side in search of food. They’ve been keeping the same nest together at least since 2010. Like all eagle nests, it is quite large and grows each year as they add sticks and freshen up the nest.


Some folks with more powerful binoculars than mine have noticed leg bands on one of the eagles. According to Kathryn Zvokel Stewart, a volunteer designated by the Department of Environmental Conservation to monitor the nest, the banded eagle is a female native to New York and born nearby on the Hudson River in 2004. The male is not banded. They are usually incubating eggs in March, and we see tend to one or two fledglings flying around in the summer.

Surprisingly, this couple stayed in the area the entire winter. Bald eagles rely on open water for fishing. When the river freezes, open water can become scarce. Unlike ice anglers, eagles can’t just drill a hole through the ice sheet to get to the fish below. Eagles either concentrate on the few remaining open water spots or travel farther south in the estuary.

By most counts, this was the harshest ice season on the Hudson River in decades. The river was locked with ice for weeks. Ice sheets held fast to shorelines and coves. The narrow channel carved by the Coast Guard ice breakers clogged with brash ice. Usually, the ice-breaking efforts of the Coast Guard open up enough water to be a boon to eagles and other fish-eating birds. Yet, with temperatures hovering near zero, broken chunks in the channel quickly refroze into a jumbled conglomeration.

During previous milder winters, we’ve seen as many as seven eagles at the Lighthouse, congregating near the open water at the mouth of the creek. This year, the extent of the ice and scarcity of open water drove many farther south to open areas such as Haverstraw Bay. Apparently, the breeding pairs stuck out the winter in the vicinity of their nests, and our local pair was no exception.

What would compel these two to stay during such a harsh winter? Perhaps to defend their breeding grounds? Who wouldn’t want to jealously guard such prime territory as the confluence of the Esopus Creek and Hudson River? How do they survive such harsh conditions instead of migrating south like the others?

The DEC’s recently published draft Conservation Plan for Bald Eagles (CPBE) provides some insights and answers some questions about our local eagle pair. Henry David Thoreau said, “Books of natural history make the most cheerful winter reading.” Although it might be a bit of a stretch to apply this adage to a government document, in evidence of the harshness of the winter, I found the CPBE to be quite interesting.

According to the CPBE, “As the bald eagle population increases and there is greater competition for nest sites, some birds may remain on their breeding territory year round or return to the nest site earlier in the year to defend their territory.” Bald eagles also have some important survival traits that were certainly put to use this past winter. They can store a large meal in their crop and digest the food over the course of several days, or can even go without food for several days. They’re also known to hunt and scavenge inland for food sources other than fish.

The successful mating of this pair is part of the larger story of bald eagles in New York State. Since New York State started its bald eagle recovery program, the population has increased from one breeding pair in 1980 to over 250 breeding pairs statewide, according to the most recent survey.

While the CPBE has a lot of good news about eagle recovery, it also lists ongoing threats—many of which could befall this local breeding pair: collisions with trains, running afoul of discarded fishing tackle, lead-poisoning from bullet fragments in carrion or disturbance of breeding or wintering sites. Those of us who are curious about the eagles and enjoy observing them can do our part for eagle recovery by making good use of our binoculars to maintain our distance from their perches.

Among the listed threats in the CPBE is degraded water quality, which can alter the availability of prey and displace eagles from their home as they go in search of better foraging. Amazingly, the local pair of eagles has survived several episodes of prolonged discharges from the Ashokan Reservoir, which fouled the mouth of the creek with turbidity for months.

On a recent misty morning, a bald eagle flew within view of the first-floor windows of the Lighthouse, no binoculars required. It emerged from the fog and swooped low over the creek with a morsel in its yellow bill. The eagle continued on its way to its nest across the river. Finding food is easier for the eagle since the breakup of the ice. After a long winter, open water is a welcome sight to everyone!

Patrick Landewe is the keeper of the Saugerties Lighthouse. His column appears monthly.