State conservation officials are asking beachgoers to not disturb piping plover nests as the rare birds return to Massachusetts this spring.
The shorebirds come back to Massachusetts' coastal beaches to nest and raise their young.
Experts say visitors should avoid marked areas where the birds nest. They also say to watch out for plover eggs and chicks, which can blend in with the sand and be vulnerable to people and pets.
Atlantic Coast piping plovers were listed as threatened by the federal government in 1986.
Government officials say that means the birds would become endangered and face possible extinction without Endangered Species Act protection.
During spring and summer, the small, stocky birds nest from Newfoundland south to North Carolina.