Keeping tabs on local osprey population helps to preserve remarkable comeback

An osprey prepares to land in its nest Friday near Haley Farm State Park in Groton.
An osprey prepares to land in its nest Friday near Haley Farm State Park in Groton. Dana Jensen/The Day Buy Photo

While he was growing up in Noank in the 1970s and '80s, David Grainger rarely saw an osprey.

Today, sightings of the statuesque brown and white hawks are commonplace for Grainger and just about anyone else who frequents the state's shoreline and river corridors in spring and summer. The birds are easily identified by their high-pitched calls, chiseled profiles and interwoven stick nests atop open platforms.

"Now they're hard to avoid when I paddle my kayak around," Grainger said during a visit to a nest at Haley Farm State Park in Groton on Friday.

That's not to say he takes the sightings for granted. Grainger, a New London resident and retired computer programmer, is doing his part to ensure ospreys continue to thrive, keeping his binoculars and observational skills keen for any signs of threat. He is one of about 65 osprey monitors volunteering for the Connecticut Audubon Society's new Osprey Nation Citizen Science project, supplying baseline data that will be used to keep track of how these once-endangered birds are doing.

"The population seems to be doing great, but we have no estimate of the total population," said Tom Andersen, communications director for Connecticut Audubon. "Now we'll be able to see whether there's any decrease in the number of nests and their productivity, and sound the alarm if there's a problem."

Information collected by the volunteers will be submitted yearly to the state Department of Energy and Environmental Protection. Included will be which nests are occupied, whether nest platforms need repairs, how many chicks are in each nest and when they fledge, and any birds with identifying leg bands.

The volunteers are each assigned to visit weekly one or more of the accessible osprey nests in the state, Andersen said. Some of the largest clusters of nests, like more than 30 located around Great Island at the mouth of the Connecticut River in Old Lyme, aren't yet in the monitoring program because of their challenging offshore locations, he said, so only 90 nests are being monitored.

"We have 274 nests mapped, but there may be as many as 1,000 around the state," he said. Many of the nests are on platforms built by volunteers, but others are on utility poles and cliffs.

Victim of DDT

The comeback of ospreys, driven to near extinction by the widespread use of the pesticide DDT, is one of the best known environmental success stories, largely credited to the attention brought to their plight by Rachel Carson in her 1962 book "Silent Spring." The pesticide entered the food chain, got absorbed by the fish that osprey ate and caused eggshells to weaken and crack before chicks could hatch.

When DDT was banned in 1972, Connecticut had only seven active osprey nests. Their resurgence was the result of the combined efforts of government agencies, conservation groups and volunteers who built platforms, Andersen said, but sustaining it requires continued attention.

Ospreys, he noted, can still be exposed to DDT in their wintering habitats as far south as Brazil, and could be vulnerable to other toxins in the environment. By keeping tabs on these uniquely visible birds of prey, experts can also gauge the health of Long Island Sound and other waterways and fish populations that ospreys depend on.

"If ospreys are doing well, we know that fish are plentiful and relatively free of environmental contaminants," said Alexander Brash, president of Connecticut Audubon. "If the osprey population starts to fall again, it will be a signal that something is wrong somewhere."

Grainger, for his part, enjoys his regular visits on foot or by kayak to the nests he's been assigned: three at Haley Farm, one at Harkness Memorial State Park in Waterford and one at the state boat launch on the Four Mile River in Old Lyme. Starting this spring, he's been spending about half an hour at each nest each time he visits, watching the osprey dive for fish, form mating pairs, feed their young and soar over salt marshes. He submits his observations via email to Audubon when he returns home.

"These are places I go for kayaking, so it's convenient. It's pretty cool they involve the public," he said as he approached one of the nests at Haley Farm, just offshore from a hiking trail. "The nest is just on the other side of these bushes. You can hear them already, that constant whistling."

j.benson@theday.com">j.benson@theday.com

David Grainger, a volunteer osprey monitor for the Connecticut Audubon Society, checks on a nest at Harkness Memorial State Park in Waterford on Friday. Volunteers like Grainger visit the nests once a week to gather data on the local osprey population and to detect any possible threats to its welfare.
David Grainger, a volunteer osprey monitor for the Connecticut Audubon Society, checks on a nest at Harkness Memorial State Park in Waterford on Friday. Volunteers like Grainger visit the nests once a week to gather data on the local osprey population and to detect any possible threats to its welfare. Halie Cousineau/Special to The Day Buy Photo

MORE INFORMATION

For more information and to view an interactive map of osprey nests in Connecticut, visit www.ctaudubon.org.

To volunteer for Osprey Nation, send an email to osprey@ctaudubon.org.If you need one, perhaps a 14 point subhead here and here

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