The Massachusetts Audubon Society will hold a “Herons at the Nest” walk next Sunday at 9 a.m. The walk will be held at the rookery, home to more than 30 pairs of great blue herons, near Mass Audubon’s Stony Brook Wildlife Sanctuary on North Street. Participants will watch the herons move about around their stick nests, built in dead trees in wetlands. Other bird species, including wood ducks and hooded mergansers, may also be spotted. Participants can meet at Stony Brook and share rides for the short distance to the rookery. Registration is required; the cost is $10, or $8 for Mass Audubon members. More information is available by calling 508-528-3140, or visit Stony Brook’s page at www.massaudubon.org.