Greenwich Time, CT – Jul 6, 2014
By Michael Dinan
Staff Writer
Published July 6 2014
Brian O’Toole stepped over a guardrail at East Putnam Avenue yesterday morning and skidded down a worn path toward the Mianus River. He came to the edge of a concrete embankment, lifted his binoculars and peered into the steel underbelly of the Post Road overpass, cars rumbling overhead.
“There’s a barn swallow that’s just picked up some nesting material, picked up some mud,” O’Toole said as the small bird darted toward a nest of grass, mud and fishing line, stuck high to a steel beam beneath the bridge. “And there’s a cliff swallow. This is the only place in Greenwich you see them now.”
Drawn to the Mianus River dam area by an unusual combination of natural feeding and manmade nesting areas, four species of swallows that originate in Central and South America can be seen hovering above the estuary through the spring and early summer.
Tree, barn, cliff and rough-winged swallows feed on tasty insects that hover over Mianus Pond, and build nests in nearby trees, on the side of the bridge and in dry culverts carved into the river’s retaining wall.
It’s very rare to see those four species within 100 feet of each other, and if conservationists get their way, a fifth type of swallow will join them, said Joe Zeranski, a lifelong resident and birder for 40 years who co-wrote “Birds of Connecticut” in 1990. Zeranski has initiated an effort to purchase and install in the dam area a house for purple martins, the largest North American swallow species.
“We’re at the northern range of the purple martin. There aren’t that many colonies in the state of Connecticut,” said Zeranski, formerly a vice president of Audubon Greenwich and member of the Conservation Commission who edits and compiles summer bird counts for the Connecticut Ornithological Association.
“They like farm land and open meadows, and much of their habitat is no longer available in the state, and without that they’re not inclined to nest,” Zeranski said.
A purple martin colony this year abandoned its house at Byram Beach for the first time in memory, O’Toole said, probably because the house wasn’t properly cleaned. The species eats massive quantities of insects every day, so people often put up houses to attract the birds. Set high up on poles, manmade purple martin houses consist either of a single structure with a dozen holes that a group of birds use to make their nests, or a cluster of gourd-shaped structures that each have a hole. Once the birds migrate for the winter, the houses have to be cleaned out to make them attractive to the birds again in the spring.
Whereas barn swallows build their nests beneath the East Putnam Avenue overpass, cliff swallows build theirs on the side of the bridge. Cliff swallows used to breed at a pump station at Putnam Reservoir, O’Toole said, but appeared to have abandoned that facility when it was remodeled.
There are dozens of martin and swallow species in the world, but the five that birders hope to see at the dam will represent all but two species seen in this area, O’Toole said. Cave swallows sometimes turn up in the fall at Greenwich Point, he said, and bank swallows typically build their homes in abandoned kingfisher nests along river fronts.
Michael Aurelia, a member of Audubon Greenwich’s science committee who voluntarily manages the dam’s fishway for the Greenwich Conservation Commission, is an active birder who often visits the area in summer to watch the swallows. Herons and egrets also regularly visit the estuary to feed on the alewives crossing in and out of the freshwater pond.
Concerned that the rough-winged swallow’s nests may be wiped out by a storm that brings a coastal surge, Aurelia said he’s planning to hang pipes higher along the retaining wall, to imitate the dried-out culverts that the birds use now. “If the nests did get wiped out, then they may not return, and I’d hate to see that happen,” Aurelia said.
Copyright © 2014, Southern Connecticut Newspapers, Inc.
