The Kennebunk Plains were just an embarrassment of riches when it came to wonderful sparrows. Field Sparrows were also breeding there. We were alerted to their presence by their song, kind of like a bouncing ping-pong ball — a musical trill that starts with from 2 to several clear whistles, then accelerates and descends into a trill. Field Sparrows have a rusty cap, a pink bill, a white eye-ring and rusty stripe behind the eye (less obvious on this worn and faded bird), a clear breast, and two white wing bars. Field Sparrows breed in much of the eastern, and part of the middle of the country in old fields with scattered bushes and trees, a habitat type which is in decline in many areas.
Similar species to Field Sparrow are Chipping Sparrow and American Tree Sparrow who both also have rusty crowns. Neither have pink bills. American Tree Sparrows have a central breast dot and they breed in the far North and come into the U.S. to feeders in winter. Chipping Sparrows commonly breed throughout most of the country, have a black eye line that extends from bill and continues behind eye. Sparrow ID is not easy, you have to look at many things on the birds.
One of the things we loved about walking back around the plains was the wonderful sense of solitude. It reminded us of being on the western prairies, or on the moors in Dartmoor, England. It was just us and the birds.