The state Department of Conservation and Recreation is reminding residents that piping plovers have begun their spring return to Massachusetts beaches for the nesting season. Plovers are a protected species under state and federal law, and the DCR and Mass Audubon work together to try to safeguard the birds on state beaches. Visitors to Winthrop Shore Reservation and Revere Beach Reservation are asked to stay out of marked areas where plovers are nesting and keep a close eye for plover eggs and chicks, whose size and coloring allows them to be easily lost against the sandy landscape. The public is also reminded that dogs are not allowed on either beach reservation from April 1 through Sept. 30. For more information, or to report any issues related to the plovers, e-mail firstname.lastname@example.org or call 617-626-4974.