Researchers track birds' movements in hopes of rebuilding population of threatened species
Waterford - As the purple martin parents circled, swooped and watched from a high perch a few yards away, Sam Thomas unlatched the door of what looked like a large Victorian dollhouse and reached into one of the shelves inside.
The house, one of three in the yard of his Jordan Cove home, usually sits atop a metal pole taller than a one-story building, but it had just been lowered with a motorized winch so Thomas and Geoff Krukar, avian researcher with the state Department of Energy and Environmental Protection, could access it. Each of the 28 shelves inside the house was serving as a nursery for four or five pearly black chicks huddled amid dried grass and reeds with open mouths seemingly large enough to swallow each other's heads.
"The adults were bringing in dragonflies late last night, until 8 or so," Thomas said to Krukar, close beside him as he cupped a small, fragile, feathered life in his palm. Krukar carefully lifted the chick from Thomas' hands and placed it inside a cardboard box, the kind used by take-out lunch vendors, but this one filled with pale blue baby blanket scraps instead of ham-and-cheese on rye with mustard.
It was the first of more than 103 young martins the two would remove temporarily from the nests that July 12 morning as part of a purple martin research and conservation project. Each of the young birds, interrupted from their short, cozy lives of the nest at a stage when they're old enough to be handled but not to fly, would get two leg bands, one blue - the color of this particular nesting colony- the other silver and stamped with a different number for each bird.
"We've got kind of an assembly line going here," said Lori Fortin, DEEP wildlife biologist, who, with three other agency staff, was stationed around a table a few feet from the birdhouse to attach the bands, weigh and check the age of each bird before returning it to its nest. Shannon Kearney McGee, an avian researcher who was part of the team, calculated most of the birds were 14 days old and weighed around 47 grams each, about as much as a large chicken egg without the shell.
The project, Krukar explained, is in its second year. Its purpose, ultimately, is to provide information that will help the state rebuild the population of purple martins, now a threatened species in Connecticut.
"We're trying to figure out the dispersal patterns of second-year birds, where they're actually going to set up new colonies, and getting their ages and weights so we can find out how healthy they are," he said.
Statewide, he said, there are about 30 known nesting colonies of purple martins, including one in Stonington. Over a few weeks in July, Krukar and his team are visiting each one, and by the end, he estimates, they will have banded 1,000 chicks. When the birds mature and start looking for nesting sites, researchers and purple martin enthusiasts can use the colored bands to identify their home nesting colony.
With that information, Krukar said, DEEP can learn how far purple martins travel from their home nests and locate new martin houses for them accordingly. Recently, he added, DEEP erected six new houses in Kent, near a known colony in that northwest corner town.
"We'd like to get more colonies established, especially inland," he said.
Thomas, a member of the Purple Martin Conservation Association and mentor "landlord" who built his first martin house kit 18 years ago, is an enthusiastic teacher about the unique habits and needs of these sociable, glossy purple-black birds, acrobatic fliers that are the largest member of the swallow family. Since starting his colony, he estimates, about 1,000 chicks have been born there.
In the East, he explained, purple martins are dependant on humans for places to nest, evolving a symbiotic relationship with Native Americans that was adopted by the colonists. American Indian tribes learned that purple martins would keep crows and hawks away from corn crops and drying hides, and hung hollowed-out gourds around their fields and villages. The martins, in turn, found that living near humans protected them from predators.
European settlers carried on the practice for many years, but as urbanization and modern agriculture techniques took over, martin houses became a thing of the past. In the early 20th century, the population was nearly wiped out by the introduction of European starlings, and today, starlings and house sparrows compete with martins for nest cavities.
"Sparrows will build a nest right on top of the martin babies, so they have to be controlled," Thomas said. "You have to watch them all the time."
South for the winter
Inside one of his houses, Thomas, who makes his living as a quality manager at an aviation parts manufacturing and supply company, keeps a video camera hooked up to a television inside his purple martin house. On the screen, he keeps tabs on the landmark activities, such as when the males come to sit on the eggs while the female feeds, and the day the chicks first hatch, emerging as tiny, pink prehistoric-looking creatures. His impressive collection of photos includes a close-up of a mother bird stuffing a dragonfly into the mouth of a baby, pinching the insect's large wings in her beak.
He first decided to put up the houses, he said, after seeing martins swooping and soaring in the area while he was kayaking on Jordan Cove. After erecting the first house, he played a recording of "martin chatter" in his yard to attract them, and they moved that first spring. Each spring, he pipes the "martin chatter" recording into his yard again.
"But I haven't had to play that for five years now," he said.
Each April, the martins return to his houses after spending the winter some 5,000 to 7,000 miles away in South America. By the time they arrive, he's cleaned out the houses and laid down a base bed on each of the shelves. The monogamous martin pairs then start collecting grasses and reeds to make the nests their own.
"I start off the season for them with pine needles in the nests," he said. "If we didn't give them these cavities, they wouldn't have a place to nest."