A baby spotted sandpiper on Napatree Point. It’s nesting and hatching time for a variety of birds on the point in Westerly.

The Providence Journal / Gretchen Ertl

WESTERLY — “We actually saw the spotted sandpiper chick.”

“We saw all three oystercatcher babies.”

Two naturalists and a summer intern were briefing a U.S. Fish & Wildlife Service coordinator at Napatree Point Conservation Area on what they saw at Napatree last week.

It sounded like a busy corner in a maternity hospital.

“Do you think they’re due this weekend?”

“It’s right around their hatch date.”

They were talking about piping plovers:

“They lay four eggs, two days between each egg. We know they’ll hatch four weeks from the second day of the third egg.”

And about American oystercatchers:

“They fledged today.”

The far osprey nest seemed empty, they reported, and there was no evidence of least tern chicks, accounting for all five of the shorebirds of interest at Napatree this time of year.

Like a Fertile Crescent for endangered birds, the Napatree Point Conservation Area is teeming with life, and naturalists hope the fragile gains that nesting pairs have made will not be swept away by the coming storm of humans on vacation.

Last Thursday three of the four naturalists hired by the Watch Hill Fire District and the Watch Hill Conservancy made their nursery rounds, looking in on nests to check for eggs, testing whether parents were resorting to “broken wing” theatrics to distract predators, counting chicks and looking for footprints and other evidence of predators.

“You really have to watch,” said Julia Royster, standing outside a roped-off area and pointing to a nest that didn’t seem to be there even though a camera taped to a stake was also trained right on it. Adult piping plovers make trips from the nest to the water and back, she said. “They look like little bits of moving sand.”

How she discovered that two of those bits had made a nest at that spot on the mile-long pebbly north side of Napatree is hard to imagine. But once nests are noted, enclosures are marked off by “symbolic fencing,” lengths of yellow rope strung on posts, and signs warning that the nests and eggs are protected.

The nests on the other side of the dunes have “exclosures,” or fencing with openings big enough for the plovers and chicks to get through, but too small for such predators as coyotes or raccoons to get in.

Napatree had six plover pairs this year, said Wendy Edwards, Rhode Island plover coordinator for the Fish & Wildlife Service. Two of those pairs have hatched six chicks since Sunday, two in one nest and four in the other.

With 40 pairs of plovers in Westerly and 62 pairs statewide, Edwards said, Rhode Island is one pair better off than last year. And that’s not counting the areas managed by The Nature Conservancy and the state Department of Environmental Management, which will be added to the Rhode Island total in the federal count.

Working egg by egg, Edwards strives to help the wild piping plover population on the East Coast reach 2,000 breeding pairs and maintain that number for five years. If they are successful, the tiny shore birds whose only defense is resemblance to sand can be taken off the Federal List of Endangered and Threatened Wildlife and Plants.

The immediate goal is to make nesting areas safe enough so that, on average, each pair can raise 1.5 chicks all the way to fledge, which is when they are able to fly. Each fledgling has to be ready for a trip to Florida or the Gulf Coast come winter. And it’s not by train.

Meanwhile, horseshoe crabs are pairing off during the full moons of May, June and July, Royster said. The larger female, carrying her mate around on her back, digs a hole at the high tide line and lays her eggs, which the male immediately fertilizes.

Those eggs make good dining for migratory shorebirds.

For two weeks, the crab eggs incubate in the sand, then they hatch into another high tide, which carries the swimming adolescents out to sea.

Royster said it takes eight years for a horseshoe crab to reach maturity, and it can live 20 years. More like a spider or scorpion than a true crab, she said, horseshoe crabs that look exactly like today’s crabs have been found in fossils 400 million years old. They are called living fossils.

Edwards shared with the naturalists a quick lesson in how plovers operate. The male, she said, will return to the nesting area where he grew up and build five nests. Demonstrating by puffing out her belly, squatting low and walking like a chicken, Edwards showed how a male plover will gouge out a circle in the sand. He might roll some egg-size stones into it, but that’s the nest. He will start guarding all the nests he’s built until the female chooses one and lays her eggs.

Then he’ll narrow his protection to that nest.

Toward hatching time, the adult birds will seem nervous at the approach of a two- or four-legged creature walking up the beach, Edwards said.

When the chicks have hatched, the adults will distract potential predators by faking a broken wing, leading them away from the nest.

Human children ages 9 to 13 can sign up to go on Tuesday and Thursday morning beach investigations at Napatree. From July 15 to Aug. 21, naturalists will lead groups of 15 children. The walks are free, but registration is required. People of all ages may join Saturday morning naturalist walks that last roughly an hour, leaving at 9:30 a.m. from the main entrance of Napatree Point Conservation Area. To register, call (401) 439-9891 or e-mail napatreenaturalist@live.com. For a calendar of the conservation area’s educational opportunities, visit www.thewatchhillconservancy.org.

dnaylor@projo.com