Terri Ackerman photographed this juvenile Cooper's hawk in Concord.

Erik Limpaecher photographed a muskrat in Concord.

Joan Chasan photographed this great blue heron at Great Meadows National Wildlife Refuge in Concord.

Steve Forman photographed great blue herons at their nests in Concord.

Steve Forman photographed a northern water snake and a muskrat at Great Meadows National Wildlife Refuge in Concord.

Terri Ackerman photographed a Baltimore oriole, its nest, and a nestling in Concord.

Terri Ackerman photographed the following in Concord, on or near the Sudbury River: a Baltimore oriole, a beaver, Canada geese, a raccoon, and a snapping turtle.

Joan Chasan photographed a Canada goose gosling, an eastern kingbird, and a great blue heron at Great Meadows National Wildlife Refuge in Concord.

Muthe Limpaecher photographed these hooded mergansers at a pond in Concord.

Steve Forman photographed a great blue heron, a marsh wren, and a song sparrow at Great Meadows National Wildlife Refuge in Concord.