The return of the fish hawk

By Bill Chaisson
Of a Feather
My father grew up in southeastern Massachusetts in the 1940s and ‘50s. He remembered driving down coast roads through the salt marshes with osprey nests on the cross ties of every utility pole. He was a sailor and spent a lot of time out on Mount Hope — he was from Swansea — Narragansett, and Buzzards bays, and in his youth, he said, when you looked down into the water, it was full of fish.

In the early 1980s he visited his friends from the merchant marine academy who had second homes on the Cape. The first thing he noticed was that the osprey nests were gone. Then he went for a sail and was appalled to see that so were the fish.

Now, my father was a bedrock conservative Republican, but in the mid 1980s when I was working for Greenpeace, he admitted that the work we were doing just might be necessary.

During the 1950s and ‘60s osprey populations plunged largely due to widespread use of DDT, which interfered with calcium metabolism and thinned the shells of their eggs. Raptors were affected because of biomagnification. DDT is fat-soluble, which means it is not excreted and so its concentration in tissues increases in each step of the food chain.

One of the vernacular names of the osprey is fish hawk. They are a single species in their own family, not closely related to other raptors. Their distinctive classification is due to several adaptations that make them able to live almost exclusively on fish. This includes modifications to its talons: sharp projections on the undersides, scales that face backward, and a toe that can reverse direction, all of which help it to hold onto fish. They also have closeable nostrils and oily feathers, which enable them to dive into the water without drowning.

Ospreys are quite large, 24 inches long with wingspans of over 5 feet, bigger than hawks and a bit smaller than eagles. Eagles are 30 inches long with wingspans to 6.5 feet, and the familiar red-tailed hawk stands 19 inches tall with a wingspan of about 4 feet. Unlike either eagles or hawks, ospreys fly with a distinct kink or crook in their wings, something like a gull or tern.

In “Water Prey and Game Birds of North America,” published in 1965, Roger Tory Peterson lamented the decline of the osprey. He had moved to Old Lyme at the mouth of the Connecticut River on the Long Island Sound in 1954. The area had been filled with ospreys; there were 150 active nests within a 10-mile radius. By 1964 there were only 17. Peterson was afraid that “one year soon” there would be no ospreys in the area.

In 1972 the use of DDT was banned in the United States, and it was then successively banned in most developed countries by the late 1980s. (It is still used in developing countries like India and North Korea.) But with the general decline in its use — and the passage of legislation like the American Endangered Species Act of 1973 — populations of raptors around the world have recovered. However, Peterson’s fears were nearly realized in Connecticut; by 1974 there were only nine pairs left in the whole state. But according to Connecticut Audubon, there are now over 400 active nests in the state, and numbers are growing.

New Hampshire Audubon began an active osprey conservation program in 1980, when the only three active nests in the state, all at Umbagog Lake in Coos County, produced no young at all. Catherine Tudish reported in a 2003 “The Outside Story” column that the previous year 17 successful nests had produced 40 chicks, and that had been the third year in a row that 40 or more chicks had been reared successfully. According to “New Hampshire Bird Records,” by 2004 there were 34 active nests in towns spread as far apart as Pittsburg, Hollis, and Littleton. Twenty-six of these nests were successful and produced 53 fledglings. By 2010 there were 70 breeding pairs in New Hampshire, which produced 90 young.

Tudish, writing in 2003, noted that recovery was going most slowly in the Connecticut River valley. I was unable to find current information on osprey distribution in New Hampshire, but N.H. Audubon notes that it was removed from the state Threatened and Endangered Wildlife List in 2008, the first to leave the list because it recovered (as opposed to going extinct).

I was surprised this week to see an osprey in Wendell Marsh in Sunapee. The wetland, which is preserved by the Ausbon Sargent Land Preservation Trust, is along Route 11 south of the Lower Village. The bird was sitting in a dead tree in the middle of the marsh, its gleaming white belly and chest facing the highway as I drove by, the black mask across its eyes also visible.

I had been primed to identify it because I had seen ospreys up close just the previous weekend in Ithaca, New York. Someone — perhaps the nearby Cornell Laboratory of Ornithology — has erected a nesting platform in Stewart Park, a city park on Cayuga Lake, since my departure in 2016. Last weekend I saw two nearly full-grown young ospreys hanging around in the vicinity of the nest, still begging for a hand-out from their parents.

Ospreys seem to take almost no notice of humans and don’t hesitate to nest and live near human settlements. Stewart Park was full of residents and tourists last weekend and the young ospreys ignored them entirely. The nest itself was at the edge of a large lawn and not the least bit secluded. When I lived in Martha’s Vineyard a pair attempted to build a nest on top of the telephone transmission tower in downtown Vineyard Haven. After their pile of sticks blew off the domed structure in a storm they continued to live in the vicinity, presumably fishing in nearby Lagoon Pond, which doesn’t have as many fish in it as when my father was a kid.