Tree Swallow

Craig Smith photographed a Canada goose, a chipping sparrow, a downy woodpecker, a gray squirrel, a tree swallow, and a yellow-rumped warbler at Assabet River National Wildlife Refuge in Sudbury.

Steve Forman photographed mallards, tree swallows, wood ducks, an American crow, and a barn swallow at Hager Pond in Marlborough.

Steve Forman photographed an American robin, a common grackle, mallards, an American crow, a red-winged blackbird, and a tree swallow at Hager Pond in Marlborough.

Lucian Vazquez photographed this tree swallow in Framingham.

Steve Forman photographed a common grackle, mallards, and tree swallows at Hager Pond in Marlborough.

Gail Sartori photographed a black-capped chickadee, a Canada goose, great blue herons, a mourning cloak butterfly, an osprey, tree swallows, painted turtles, ring-necked ducks, a song sparrow, and a white-tailed...

Gail Sartori photographed these tree swallows at Assabet River National Wildlife Refuge in Maynard.

Steve Forman photographed a black-capped chickadee and a tree swallows at Mass Audubon's Waseeka Wildlife Sanctuary in Hopkinton.

Steve Forman photographed a four-toothed mason wasp, a red-tailed hawk, a barn swallow, and a tree swallow at Breakneck Hill Conservation Land in Southborough.

Steve Forman photographed a tree swallow at Delaney Wildlife Management Area in Harvard.