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|Duxbury's "fish hawks"|
|Written by Brennan Murray|
|Wednesday, 10 July 2013 08:47|
12 healthy osprey chicks banded in annual Audubon eventAtop a shaky wooden post on Scat Island, Mass Audubon's Norman Smith stood face-to-face with two baby ospreys, their chests puffed out and wings poised to fend off the unusual intruder. Below, two Duxbury Conservation employees steadied a ladder in place.
Nudging the birds back with bare hands, Smith reached into the nest and pulled out a four-week-old chick, whose gnarly talons were already fully mature - and razor-sharp. Placing an aluminum numbered ring on this younger sibling's left leg, he commenced the annual banding of Duxbury's thriving fish hawks.
Smith, Sanctuary Director at the Blue Hills Trailside Museum, was lucky to make it down without injury. In over two decades work- ing with the species, not all of his experiences have been bloodless. Ospreys have knife- like beaks they use to shred through scaly skin.
Forty years ago, these fish-grabbing predators didn't nest in Duxbury's abundant salt marshes or anywhere else on the South Shore. Instead, researchers only found large populations on Martha's Vineyard and the banks of the Westport River near Buzzards Bay. Once on the Massachusetts threatened list, ospreys are now flourishing again in new areas.
Since 1970, Smith and other helpers, like Duxbury Conservation Administrator Joe Grady, have banded over 250 ospreys, many of them in the six nests scattered between the northern salt marshes and Hicks Point Road. There are now 20 nests between Quincy and Plymouth, and the bands help researchers like Smith keep track of the inhabitants within.
Grady could only recall five returned birds out of the hundreds he's banded. One was shot in Cuba, another in the Cayman Islands and three were hit by airplanes. For Grady, five deaths are a small price to pay for a conservation effort that's yielding strong results.
Last week, Smith, Grady and a group of 15 other Audubon staff and interested onlookers banded a dozen baby ospreys in Duxbury, ranging in age from one– to eight– weeks. Researchers have also observed them moving farther inland over the last few years, taking up residence near ponds in Weymouth and even by Walpole's Cedar Junction prison.
"Ospreys are good environmental indicators," Smith said. "Generally speaking if they are doing well the area around them is healthy too."
With just a few natural predators like raccoons and great-horned owls, ospreys find the tall man-made poles in Duxbury's marshes to be suitable spots for raising families. One observer, who is in the oyster business, said he has seen adult ospreys dive down and struggle back up with full- size striped bass clenched in their claws.
Scientists in Scotland discovered that these raptors are able to predict the precise location of prey by calculating the amount of light refraction fish produce at the surface of the water. This advanced skill is especially useful for parents who have to feed their unfledged young, like the one- week-old baby Smith retrieved from a nest north of Powder Point Bridge.
An osprey this young can't stand or fetch food on its own. Without feathers, a week-old bird like this one also runs the risk of getting hypothermia if his mother and older siblings don't deflect rain away. Though too tiny to be banded, Smith debunked the rumor that its parents would reject it due to human contact.
At the end of the summer, osprey mothers migrate down to the Caribbean or beyond while fathers stay in the nest to teach the youngsters how to hunt. Once September comes around, the whole family will head south. For now the chicks must grow, eat and learn to fly. If they survive there's a chance they could live over 25 more years.
Just beyond Clark's Island, in a recently reconstructed nesting pole, Smith climbed the ladder once more before he and the crew returned to the Town Pier. With another osprey in a careful grasp, he let everyone around feel the eight-week-old's soft feathers.
A little past 10 a.m. and it was already the tenth chick of the day. Without making a sound, the baby returned to a spot close to his sibling, blending in perfectly with the dark- colored sticks and branches that made up the nest.
"Nature is an amazing thing," Smith said.