SEABROOK N.H. (AP) – Four have hatched so far but only two survive.

Volunteers and state wildlife officials are watching closely and trying to protect a pair of endangered piping plovers chicks born less than a week ago. Two of the young birds already have disappeared, likely killed by predators.

Piping plovers are small tan and white birds similar to the sandpiper. The birds, which range from the North Carolina coast to Newfoundland, have been dying off since the 1940s as development spreads and beaches become more crowded.

The state Fish and Game Department has been tracking the birds since 1996. To date, 74 chicks – described as “cottonballs on toothpick legs” – have successfully fledged in New Hampshire.

Wildlife officials are urging beachgoers to watch where they walk. The plover is hard to see and hunkers down in the sand when threatened. The adult birds have bright orange legs and a black line across the forehead and around the neck.

In early May, one pair of piping plovers laid four eggs at Hampton Beach. Three of the eggs disappeared and the one chick to hatch also vanished.

Wildlife officials say high tides, seagulls, cats and humans all pose a danger to the young birds, who will be unable to fly for their first month of life. The chicks wander around the beaches looking for food.

“Being unable to fly makes them extremely vulnerable,” Murphy said.

Concern for the birds has brought out volunteers, who are walking Seabrook Beach to warn beachgoers about the young chicks. Many were relieved after a close call earlier this week when the two surviving chicks were seen feeding on the inlet side of the seawall as the tide was rising.

“Last year some chicks got stuck on this side and weren’t able to get back over the jetty,” said Kristen Murphy, of Fish and Game. Those chicks were swept out to sea. “That’s just one of the issues with trying to keep these birds alive,” she said.

Another pair of piping plovers has a nest with four eggs at Hampton Beach and those chicks are expected to hatch shortly.

Federal Fish and Wildlife Service officials are worried about stray cats and recently ordered a local feline rescue service move its feeding stations away from Hampton Beach.

The organization’s president Carol Ritchie has said her group will not comply.