By JOHN RICHARDSON

Blethen Maine Newspapers

The Maine coast has become a hard place to live for terns, what with hungry gulls, shrinking habitat and other threats.

The family of small black, gray and white seabirds is getting by, however, with a lot of help from biologists and caretakers.

Last month, the people behind that effort had a scare. Gulls took advantage of a storm that kept caretakers away from Seal Island off Rockland. Over a period of a few days, the gulls had a feast.

"They went in and ate up the eggs of at least 2,000 nesting pairs" of terns, said Stephen Kress, director of the National Audubon Society's seabird restoration program. "The whole colony was gone by the time our staff was able to get back out there."

When they returned, the island caretakers walked around the island to scare off the gulls, and many of the terns came back and laid new eggs. The rest of the terns moved to nearby Matinicus Rock and nested there. In the end, said Kress, "we don't think we lost any of them." Trying to maintain and restore coastal and island tern colonies is a constant struggle that involves a small army of federal, state and private scientists, some of whom spend summers on nine otherwise deserted islands to protect and monitor the birds. Guardians on the island and on the mainland are trying to keep nests safe from gulls, crows, foxes, minks, dogs and beachgoers. And they're trying to restore island nesting areas that have become overgrown with vegetation.

While tern populations were first decimated in the late 1800s because people shot them and collected their eggs, their recovery has been complicated by such modern threats as development around their coastal habitat and an overgrown gull population that used to feed in open landfills and is now scavenging for other sources of food.

"If we weren't out there to manage the vegetation and chase the gulls off, the terns wouldn't have a chance," Kress said.

Common, Arctic and federally endangered roseate terns live on a network of Maine islands, including nine restoration islands that are managed actively by the U.S. Fish and Wildlife Service and Audubon. The populations have been growing, although not at the rate hoped for by federal and state agencies.

The number of nesting pairs of terns in Maine has grown from about 5,320 in 1977 to about 11,212 last summer. Scientists also worry that the birds remain too dependent on a handful of small islands, any of which could be visited by predators such as the gulls on Seal Island.

"It was quite a rough start to the season," said Brian Benedict, deputy manager of the U.S. Fish and Wildlife Service's Maine Coastal Islands National Wildlife Refuge, which includes Seal Island.

The terns on Machias Seal Island off Cutler weren't so fortunate. The state's largest Arctic tern colony was decimated last summer when gulls came in and ate the eggs in 1,600 nests. They did not renest and still have not recovered there, Benedict said. "My understanding is they did not nest this year."

There has been some good news for terns this year.

The Patriots Day storm that damaged tens of millions of dollars worth of property and took down many bald eagle nests actually helped restore habitat for least terns. The storm hit just before nesting season, and it scoured away overgrown vegetation from Stratton Island off Scarborough, one of several islands where caretakers have been working to cut back the growth and expand gravel nesting areas.

"If that storm came a month later, it would have washed off the tern nests," Kress said.

Instead, it made more room for least terns, a smaller and less common variety of birds that have been relocating from sandy mainland beaches to Stratton for the past two summers. "The storm just really improved the habitat for them," Kress said. Scientists recently counted 113 pairs of least terns on the island, where they are safe from development pressures and less vulnerable to predators.

"It's almost the whole state population, and they're doing very well," Kress said. "The neat thing is they've moved to a wildlife sanctuary. ... The big concern would be that all their eggs are in one basket now."

There are still some least tern nests on mainland beaches, but not many. Biologists from the state and Maine Audubon try to protect them from beachgoers, dogs and suburban predators such as crows and foxes.

"We have just a single pair at Wells Beach, and right now they've got a chick that's about 11 days old," said Joy Felio, Maine Audubon's piping plover and least tern project coordinator. "It's out in front of some houses and just has this little tiny area with string fencing."

Felio also monitors the plover, a small shorebird that is even more threatened because it nests only on mainland beaches. "We had about 35 pair this year statewide," Felio said.

Scientists say they remain optimistic about terns because they clearly respond to the intensive management on the islands, but there also is no end in sight to the work.

"We want to give these birds all the chances we can," Bendict said. "Until gull populations get to a level where they were historically, I think we're going to be in this at least for the foreseeable future."

Human intervention is unavoidable, Kress said.

"It's not a natural system, and we know that because of how crowded the Maine coast is," he said. "Managing for biodiversity has to be a planned and ongoing process, but we can do it."