The spectacle of an osprey—a powerful raptor with a six-foot wingspan—plunging into the water from a height of a hundred feet and emerging with a fish in its talons might suggest invincibility. Yet this bird has struggled to regain a foothold in our part of northern New England. Here, as elsewhere in the U.S., osprey populations were decimated by the widespread use of the insecticide DDT during the 1950s and 1960s. But they are now making a comeback; ospreys remain a threatened species in New Hampshire but have just come off the endangered species list altogether in Vermont.
Fully grown, an osprey is 23 inches long and weighs approximately four pounds. Occasionally mistaken for the much larger bald eagle, ospreys have dark plumage on their upper wings and backs, white undersides, and white heads with a distinctive dark eye stripe. The only raptors to plunge into water feet first, ospreys have short barbs on the bottoms of their feet and sharp talons to help them seize and hold onto their slippery prey.
Because ospreys eat mostly fish, they are found near rivers, lakes, and coastal waterways. Once plentiful along the coast of southern New England, increasing development began to drive them away by the late 1800s. They continued to thrive in less developed areas until the effects of chlorinated hydrocarbons such as DDT caught up with them. Though remarkably adaptable—ospreys are found on every continent except Antarctica and have even nested on light towers in a New York City parking lot—they were defenseless against chemical contamination.
Rachel Carson published Silent Spring in 1962, demonstrating the connection between DDT and the reproductive failure of ospreys and other birds, including falcons, hawks, and eagles. But it was another 10 years before DDT was banned nationwide, and by then, ospreys were no longer breeding in the Northeast.
Today, however, ospreys can once again be seen along the Connecticut River and smaller bodies of nearby water in mid-April and early May as they migrate to their breeding areas. The success of their recovery thus far owes a lot to human intervention.
According to Steve Parren, chief of the Nongame and Natural Heritage Program of the state’s Fish and Wildlife Department, ospreys are “doing exceptionally well in Vermont” because of artificial nesting platforms built in partnership with electrical utility companies, starting in 1987. In 1986, the Department recorded only one osprey nest in Vermont, and it produced no fledglings. By 2002, that number had grown to 39 successful nests and 68 fledglings.
A single osprey generally lays three eggs, and the ideal nesting site is in a treetop near water and separated from other vegetation at nest height. By providing platforms, Parren explained, his group was able to create the preferred nesting situation and also protect the sites from weather and predators.
In New Hampshire, the state Audubon Society, the Fish and Game Department, and Public Service of New Hampshire have been working together on a similar nesting program, according to Chris Martin, senior biologist with the Audubon Society. Their success, Martin said, is “ongoing, but not as dramatic as Vermont’s.” In 1981, he pointed out, three osprey nests in New Hampshire produced no young. In 2002, however, 17 successful nests produced 40 chicks, marking the third year in a row with 40 or more young.
Ospreys build nests from sticks and driftwood, lining them with soft materials such as moss and seaweed, and, occasionally, old clothes and even shoes. After wintering in Central and South America, New England’s ospreys return to their breeding grounds in the spring, usually to the same nest—which they add to each year with new materials.
Although the Connecticut River is a major migratory pathway, Martin said it has been a challenge to restore ospreys to this watershed. To his knowledge, there are no osprey breeding pairs in the Upper Valley. Parren agreed, noting that Vermont’s ospreys are nesting in the Champlain Valley, along the Missisquoi River, and in the Northeast Kingdom. In New Hampshire, they are found along the Androscoggin River, Great Bay, the Connecticut Lakes, and the upper Merrimack River valley. A nesting platform erected in Lyme, New Hampshire, in 2001 has yet to be used, though plans are underway to build more platforms in the Upper Valley region.
Anyone observing osprey activity, especially nesting, is urged to call the Vermont Fish and Wildlife Department at 802-879-5669 or the Audubon Society of New Hampshire at 603-224-9909. People are advised not to get too close to ospreys but to enjoy them through a pair of binoculars.
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