The state now boasts more than a third of all the piping plovers along the East Coast.

HADLEY, Mass. (AP) – By now, the lonesome whistle of the piping plover is long gone from the state’s windswept beaches.

The demure little sand-colored shorebirds are dipping their orange feet in warmer water, on beaches in Florida and the Caribbean. But how many will return in the spring to the Massachusetts beaches where they have regained an uncertain toehold remains an open question.

Last spring’s oil spill in Buzzards Bay “was a real wake-up call,” said Scott Melvin, a biologist with the state’s endangered species program, underscoring the vulnerability of the tiny birds, even in the state that has been most successful in their restoration.

The April 27 spill polluted more than 53 miles of coastline just as the plovers were beginning to nest on the bay’s beaches. Still, Melvin is cautiously optimistic.

“We may have dodged a bullet,” he said. About 80 plovers were found oiled to some degree, but they continued to nest and the species suffered far less than the loons, waterfowl and seabirds that were oiled by the hundreds.

Still, Melvin and Susan von Ottingen, a biologist with the U.S. Fish and Wildlife Service, said it remains unclear if the little birds classified as threatened by the federal government – one step below endangered – were weakened to the point where they could not withstand the rigors of migration.

The piping plovers and man come into conflict because the birds with the distinctive black head band and collar “occupy territory that is highly desirable to us,” von Ottingen said.

They nest on sandy beaches from Memorial Day to nearly Labor Day and their primary defense is camouflage.

Their eggs and chicks are nearly indistinguishable from the sand and their ability to fade into the background became a disadvantage as their numbers took a sharp drop after World War II, when more humans and off-road vehicles headed for the beaches.

After more than 15 years of periodic beach closings to off-road vehicles and swimmers during the summer breeding season, Massachusetts now boasts more than a third of all the piping plovers along the East Coast, and 80 percent of those in New England.

Preliminary tallies showed 510 pairs of piping plovers nested at more than 100 Massachusetts beaches this summer, up dramatically from the 126 pairs counted in 1987, but a dip of 5 percent from the 538 pairs the previous year, Melvin said.

“It puts a lot of responsibility on us,” he said. “But we’ve shown it can be done with a lot of work and cooperation by a lot of people.”

Earlier this month, federal wildlife officials at the service’s regional office in Hadley forgave the town of Plymouth a $12,000 fine they had asked a federal judge to levy in 1998, but never collected.

The legal battle was the first over the plover in Massachusetts and was launched after a chick was found killed by an off-road vehicle on the town’s Long Beach, a popular sand spit stretching nearly three-miles across Plymouth harbor.

“It’s long over,” said von Ottingen, praising the accommodations the town has made since to protect the 2-ounce shorebirds.

“The regulations are telling communities you have to find a middle ground,” said David Gould, Plymouth’s natural resources director.

The town flags the nests and restricts off-road travel around them while they are active. How much of the beach is off-limits to vehicles depends on where the birds settle.

The Plymouth plovers are flourishing. “We had 21 chicks fledged this year, the most ever,” Gould said, and despite some complaints, the town continues to sell between 2,000 and 3,000 off-road permits annually to drive on the beach.

Man isn’t the only problem plovers face. Crows, skunks, red foxes, gulls and coyotes all raid the nests. Every summer, Massachusetts communities and other groups hire up to 100 plover wardens to watch over the nests and help protect them with mesh cages.

And the little birds that dart about the high-tide line can delight.

“They are incredible to watch,” said von Ottingen, recalling the plovers quickly became a favorite of the oil spill cleanup workers. “Especially, when you think about their fragility and how much it is up to us whether they will survive.”