Stepping off the landing craft onto Great Gull Island can feel a bit like entering a missing chapter of "Alice's Adventures in Wonderland," where a peculiar society of humans willingly subjects itself to all the rude and intimidating behavior that some 20,000 small birds can muster.

On shore, an elderly woman with one male and two female assistants, wearing shirts stained with bird poop and battered straw hats festooned with fake flowers, gave each person getting off the boat a 3-foot dowel rod as a defense against the perpetually swooping, screaming dive-bombers.

"Just come along and hold the sticks overhead," Helen Hays, the grandmotherly steward of the Southold, N.Y., island since 1969, told the group that landed there July 17.

"And watch every step you take, because there are eggs and chicks everywhere."

The followers trekked up a sandy path behind Hays, stopping when she pointed out a fuzzy newborn common tern amid a tangle of grasses and wildflowers, then an older chick making its first attempt to become airborne.

"He really wants to fly," Hays said as she watched the fledgling flap awkwardly.

The dozen visitors, ferried 7½ miles across Long Island Sound from Waterford, had come with a special mission: to help keep this seemingly remote, 17-acre island in the middle of one of the busiest waterways on the East Coast an optimal sanctuary for the birds who call it home.

Owned since 1949 by the American Museum of Natural History in New York City, the island hosts the world's largest nesting colony of common terns - about 9,500 pairs each summer - and the largest colony in the Western Hemisphere of their federally endangered, more timid cousins, roseate terns - about 1,300 pairs.

"This is my third trip out there in the last two years, and each time, with all the birds, it's overwhelming," said Juliana Barrett, associate extension educator with Connecticut Sea Grant, based at the University of Connecticut's Avery Point campus in Groton. She organized the hour-long ride to Great Gull, between Plum and Fishers islands.

The experts will consult on Sea Grant's ongoing work with Hays to make the habitat more hospitable and to compensate for some of the damage wrought by Superstorm Sandy in 2012. In the spring, Barrett and Hays joined forces to airlift a load of lumber to the island from Groton-New London Airport. The lumber was used to build nesting terraces for the roseate terns, who were shut out of many of their preferred rock crevices when the storm left them clogged with sand.

The group of ornithologists, coastal engineers and habitat specialists brought together by Barrett spent the day touring the island, including the network of decaying tunnels and concrete gun emplacements left over from the island's former incarnation as Fort Mitchie from 1896 to 1948. Terns at all stages of life populate the abandoned structures and the rocks, dunes and meadows in between, congregating there each spring to nest and rear their young before flying to South America for the winter.

Since taking over the island, the venerable Manhattan museum's goal has been restoring and fostering expansion of the colonies, each summer supporting teams of researchers and volunteers who band, count and observe the birds under the oversight of Hays, the project director, and Joseph DiCostanzo, who directs the trapping and data collection. The project has produced some of the best and most comprehensive data on the two species, making the island a source of continuing interest for researchers from as far as Argentina and Brazil, where the terns migrate in the winter.

"A lot of doctorates in ornithology have started out on Great Gull," said Grace Cormons, a Virginia resident who has spent several weeks on the island every summer since 1988, leading the banding and counting of roseate terns.

"It's a learning ground," Cormons said.

The main problem at Great Gull, Barrett said, is how to thin the thickets of wild radish that are taking over, choking out other plants that leave the landscape more open and conducive to nesting. Meadow voles introduced onto the island in the early 1980s brought some invasive grasses under control, but the remaining voles won't eat the radish plants. Barrett is hoping the experts will come up with some ideas for ridding the island of radish without resorting to pesticides or other means that could harm the birds. They would then work with Hays, the U.S. Fish & Wildlife Service and others to apply for grants to carry out the work.

"The wild radish has just gotten a foothold here, and it's too thick for the birds to nest," Barrett said. "This is a very special place, but it's still a struggle to maintain this habitat."

Human threats

For their one-day Great Gull crash course, Barrett's group split into two, each following one of the volunteers around the island, learning about their work.

Dick Young, a school bus driver from Naperville, Ill., first volunteered on Great Gull in 1981 through a program offered by the community college he attended.

"I liked it so much I've signed on for almost every year after that," said Young, who led one of the groups and is well versed in the island's history. "This is my 32nd year."

He stays for six weeks each summer, as do the other volunteers, sleeping on simple cots in the abandoned Army barracks, without access to television or convenience stores, using a pit toilet and a shower supplied by rain water. Diesel generators fill power needs, and a boat from Waterford brings supplies weekly, including special requests such as ice cream, and sour cream and onion potato chips.

Young and the other volunteers usually start trapping and banding the terns around 6 a.m., breaking after a few hours for breakfast and then returning to work until lunchtime. They take a break at mid-day, and then return to work from late afternoon to early evening, when they gather for a group meal in the rustic kitchen.

"Every year I come back, the birds are surprised by our presence," Young said. "They still treat us as a threat. Some are very aggressive, and draw blood when I pick them up to band them."

So far this summer, Young and the other volunteers have banded 5,500 chicks and have provided a footnote for future researchers to ponder - many of the clutches were smaller than normal this year, one to two eggs compared to the usual three or four.

Maria Anderson is a college senior and a summer research assistant on a project that implants the birds with radio transmitters so their flight patterns can be tracked by radar. She arrived in June and, after some initial adjustment to life on the island, she's come to appreciate being in such a unique environment.

"Your first night, it's a little uncomfortable," she said. "You're living in a concrete tower and there are holes in the walls and birds screaming at you all the time. But now I love it out here, living with the birds. I can identify individual birds now by their calls."

Georgia Male, who grew up in Old Lyme and Chester, began volunteering at Great Gull with her father about six years ago. She is spending this summer back on the island before starting her freshman year at Unity College in Maine, where she plans to study captive wildlife care and education. She said her experience at Great Gull not only helped her decide that she wanted a career working with animals, but also, perhaps ironically, it helped her overcome her shyness around humans.

"I was 13 or 14 when I first came here, and working with all the different people older than me gave me better people skills," she said. "And I've learned more about the science of birds here than I ever would have out of a book."

Discoveries and fun

Central to all the positive feeling volunteers and others express toward Great Gull is Hays, whose steady, caring presence puts others quickly at ease. In the six months of the year she's not living on the island, she lives in a place that could hardly be more of a contrast - Manhattan. There, out of an office at the museum, she works on the tern data collected during the rest of the year and, she said, she spends as little time outdoors as possible.

"I couldn't keep doing this unless it was fun," said Hays, who is probably in her 80s but won't reveal her age. "We keep finding out new things about the birds, and that's very exciting."

Discoveries that resulted from research on Great Gull include the location of the terns' wintering habitat - a find that led to a long-term relationship with South American ornithologists - and evidence that PCBs were getting into the food chain and causing some of the chicks to be born with birth defects. Years of banding and tracking returning birds has brought a better understanding of their mating behaviors and has revealed that the terns' lifespan can be as long as 27 years, perhaps longer.

"We are a sanctuary for both species. We act as a kind of safe place for them in a world where there aren't many safe places," Hays said.

But Hays' commitment alone would not have been enough to sustain Great Gull and the network of loyal volunteers and donors who have kept it - and the terns - going, Cormons said.

"It wouldn't work if she didn't have the connection both to birds and to people," she said. "This is a project you can't do single-handedly."

While modest about crediting her own personality with Great Gull Island's success, Hays nonetheless acknowledged that giving up her work there, when that day comes, will be difficult. Her gait this day was hobbled as she traveled the uneven footpaths around the island, and she admitted that she's begun thinking about who might succeed her.

"I have to find someone else willing to do this," she said. "It is a little daunting."

j.benson@theday.com