NAVARRE BEACH — About 40 volunteers turned out Thursday to place signs and fencing along the Navarre Beach causeway to protect least terns and black skimmers that soon will be nesting in the sandy areas along the road.

"For the past few years we've had somewhere between 60 and 120 black skimmers nesting out here," said Caroline Stahala, the Panhandle shorebird program manager with the Florida Audubon, which organized the volunteer effort. Stahala said there also has been somewhere between 80 and 150 least terns nesting along the causeway.

"Both species of birds are listed as threatened in the state of Florida," Stahala said. "And since we have a group nesting here, we do all we can to protect them and make sure that they have a safe place to nest."

Stahala said the birds, which nest in the sand, might prefer the causeway because vehicle traffic keeps potential predators away from their nests.

About a half dozen of the distinctively colored black skimmers flew around the causeway Thursday, passing over motorists and volunteers as they worked.

The birds should start nesting later this month or early May, with eggs starting to hatch in June, according to Stahala The tern and skimmer chicks will stay in their nests adjacent to the causeway until they are ready to fly south with their parents sometime in September.

"These birds are pretty spectacular. Roll your window down, take a look at them," Stahala said. "The one thing that we're going to ask is that people drive slow as they're coming across the causeway," to avoid hitting low-flying birds.