Nature Notes: Osprey’s return a conservation success story

Ospreys are the only hawks that dive for fish. (Photo by Bill Hobbs)
Ospreys are the only hawks that dive for fish. (Photo by Bill Hobbs)

The osprey is a familiar resident on our Connecticut shorelines. This raptor — the only one who dives in the water — usually starts its fish-hunting routine in the early morning or late afternoon, climbing to about 100 feet or higher, wheeling in ever widening circles until they spot their prey.

Then they quickly descend to about 30 feet, fold their wings and hit the water full-force, with talons outstretched, plunging as deep as 3 feet to seize their quarry.

“I love the way ospreys hunt,” said Mark Bullinger, naturalist and director of recreation for the Weekapaug Inn. “They hunt heading into the wind, so they can fly slower and spot fish.”

How good are they at catching fish? According to scientists, ospreys capture fish an average of 8 out of 12 attempts. That’s a 67 percent success rate. Not bad.

We fisherman, who hunt stripers, blues, fluke and flounder, with the fanciest fish-finding gear and tackle, only wish we could be that successful.

Keen eyes, wicked talons and great gripping pads on the bottoms of their feet allow this impressive bird of prey to pull out of the water slippery fish weighing up to two and a half pounds.

The osprey’s scientific name (Pandion haliaetus) comes from Pandion, the mythical king of Athens, whose daughters were turned into birds, and the Greek words “halos,” referring to the sea, and “Aetos,” or eagle, according to the website explore.org.

These beautiful birds of prey usually mate for life and can live long lives. The oldest recorded osprey lived 25 years in the wild.

Ospreys also build huge stick nests on treetops, telephone poles, channel markers or human-built nesting platforms, some measuring 10 feet across and 3 feet deep, returning to them year after year to add a stick or two during courtship rituals, or to refresh the interior with seaweed and grasses, before raising their young.

The osprey nest that I recently observed and hid below in my car for an hour to take photographs for this column was built on a utility pole behind the Wadawanuck Yacht Club in Stonington.

It’s an odd location – abutting the railroad track — but the ospreys seemed undeterred by commuter trains whizzing by, and, I’ll give them credit: These birds chose a site with an outstanding view of Stonington harbor.

Edward Lamoureux, co-chair of the Alewife Cove Conservancy, emailed me about another osprey nesting site, one very close to human contact.

“We have a unique osprey nest in the parking lot of Ocean Beach in New London,” he said. “It’s located in the light tower, and that nest has been there since 1939, a year after the 1938 hurricane swept through, and Ocean Beach Park was restored with that light tower.”

If food is abundant and predators like racoons or owls don’t rob the nest, a pair of ospreys may raise one to four chicks each year. The chicks hatch after 36 to 42 days and take their first flight within 51 to 54 days.

Then, by early fall, ospreys migrate south, down to the next continent. How do we know?

“Scientists now track ospreys by strapping lightweight satellite transmitters to the birds’ backs. The devices pinpoint an osprey’s location to within a few hundred yards and last for two to three years.

During 13 days in 2008, one osprey flew 2,700 miles — from Martha’s Vineyard to French Guiana, South America, according to allaboutbirds.org

Finally, these wonderful birds are a conservation success story.

The osprey’s comeback from the ravages of DDT, a pesticide that thinned their egg shells and almost brought these and other raptors to the brink of extinction in the 1950s and 1960s, is extraordinary.

For example, Rob Bierregaard, an ornithologist who has been studying ospreys on Martha’s Vineyard since DDT was banned in 1972, wrote on his website, ospreytrax.com, “In 2017, we completed the 20th survey of the island’s ospreys. The population is now over 90 pairs. Quite a jump from the two pairs that were on the Vineyard in 1971.”

Connecticut’s ospreys are also showing successes.

In 2016, for example, a citizen science-based group called Osprey Nation, led by the Connecticut Audubon Society (ctaudubon.org), located 294 active osprey nests statewide, with 490 fledglings, versus 394 active nests and 607 fledglings in 2017, promising hope for the bird’s survival.

“It’s been a delight to see the osprey’s return,” said Andy Griswold, director of ecoTravel for Connecticut Audubon. “They add beauty to our landscape.”

If you know of similar wildlife stories or sightings, please drop me an email with observations and I will gladly write about them. Feel free to enclose photos you might have taken as well. Enjoy.

Bill Hobbs is a resident of Stonington and a life-long wildlife enthusiast. For comments, he can be reached at whobbs246@gmail.com.

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