MARION — “Let’s hope they go for the stick instead of your face,” Carolyn Mostello said as she took a reporter’s hat and readied it for Bird Island by duct-taping a wooden paint stirrer to the back, sticking up like an antenna. “And whatever you do, don’t look them in the eye.”
Mostello, a coastal waterbird biologist for MassWildlife, the state’s conservation agency, clearly loves the ritual of preparing, and scaring, first-time visitors to Bird, one of the three islands in Buzzards Bay that she has nurtured into a nirvana for terns, and a waking nightmare for the scientists who care for them. The fact that her clothes look like she lost an epic Wite-Out fight only adds to the effect.
Not that there’s any real way to prepare someone for the sensory overload that is Bird Island. As Mostello steers a boat toward the 2-acre island just outside Marion Harbor, the sound grows from a dull roar to a shattering shriek, and with it the realization from the crew — five young student volunteers — that they are going to spend the next five hours trapped inside a Hitchcock movie, under constant attack from the common terns and endangered roseate terns whose nests they have come to count.
“The first day here, I thought I was going to die,” said Adriana Pastor, a Bates College student on day three as a volunteer. “I was honestly wondering if I would ever see my family again. I wanted to leave. But now, I kind of love it.”
What’s not to love? For starters, you need to walk like a teenager sneaking in after curfew. Gentle, slow tiptoeing whilst watching out for the tiny, camouflaged eggs that are everywhere this time of year. While you do this, the moms and dads will express their displeasure by ramming the stick, your back, your anything.
Or they will simply hover in your face, shrieking, daring you to look them in the eye, which you can’t do because 1) you like your eyes where they are in your head; and 2) you need to be looking down to make sure you don’t step on an egg or a chick, the first of which were just hatching on this day.
And then there are the endless bombing runs, which quickly become strangely routine, save for the occasional groan from one of the students, followed by, “That one went down my back.”
It is madness. But it is also part of a miracle.
For since 2000, when Mostello, now 53, took over as project manager for MassWildlife’s tern restoration project in Buzzards Bay, the number of endangered roseate terns in the bay has doubled. Last year, researchers counted about 3,000 nesting pairs on the three islands; that number constitutes half of their total population in North America.
It’s something to be proud of, but Mostello said equally satisfying has been watching the development of the 100-plus young biologists who have worked on the project through the years, gaining incomparable field training.
“Being able to work in the high-pressure environment of a seabird colony is something valuable to put on your resume,” Mostello said. “It’s not like working at a desk. And it’s not for everyone. Some like it, and that’s good to know. There’s also a lot who don’t like it, which is also good to know.”
Sydney Jones, a UMass-Amherst undergrad from Westford, was back for her second year volunteering for the count. “I love it,” she said. “Yes, there are moments when you feel like you just need a break, but then you’ll see an adorable chick — they will actually crawl underneath you for shade — or you’ll see an adult do this cute thing where they kind of wiggle down onto their nest on top of their eggs and make this ‘happy tern’ sound, and that makes me happy.”
For the count, the island is marked out in a grid, and the crew members line up a few feet apart and slowly walk through each section, counting the nests. To make sure they don’t count the same nest twice, they place a tiny piece of leaf in each nest to show it has been tallied, an action that enrages the birds, who don’t like anyone going near their eggs.
All the while, Mostello and the small full-time staff who work on the project are also looking out for other management issues. “Seabirds aren’t a species where you can do something one year, then do something 10 years later, and expect them to thrive,” she said. “They require hands-on conservation every year, or the colonies will decline.”
That includes such things as keeping the foliage from getting too overgrown. Common terns like to make nests in the open. Roseate terns are the opposite; they like a little bit of shrubbery for cover, or they nest inside the dozens of tiny wooden lean-to shelters the MassWildlife staff maintains. The birds look very similar (the common terns on the island have an orange bill this time of year, while the roseate bills are mostly black) and their eggs are tricky to differentiate, with subtle differences in shape and contrast. Mostello is often called over to adjudicate.
And then there is the endless task of keeping an eye out for predators. On Bird Island, workers are currently trying to trap a mink that has made the 1-mile swim from shore and killed dozens of birds. Other years it’s been raccoons and even deer (though they aren’t much of a problem and eventually swim off).
It’s a lot. And it’s constant. And the chaos never really shuts off until the birds migrate south in the fall.
The only real escape on Bird Island is an old lighthouse at its center, and when Mostello climbs the spiral staircase to the catwalk at the top, she allows herself a moment to look out on the sea of birds flying every which way below and feel a sense of accomplishment.
“It’s amazing when they’re all up in the air like this, isn’t it?” she said. “You get to watch this thing grow, like a garden. Except we’re growing terns.”
Billy Baker can be reached at billy.baker@globe.com. Follow him on Instagram @billy_baker.