I offered this photo as a "mystery bird" to my email friends. Thanks to those who bravely guessed this bird. First place honors go to Elisabeth Köster and Paul Donahue who were the first to submit the correct answer. Their emails arrived literally within seconds of each other. As several of you guessed, the bird was an American Pipit (Anthus rubescens) in breeding plumage. This species goes under the name Buff-bellied Pipit in European literature and the photo shows the buff-colored underparts which this species gets in the breeding season. At that time the underparts may be largely unstreaked.
This pipit had been foraging along the edge of one of the ponds when it flew up into a nearby tree where the photo was taken. This species normally forages on the ground, but often will sit up on fences. However, I rarely see them sitting in trees. Other guesses included Varied Thrush and Townsend's Solitaire (one vote each) and Swainson's Thrush (several votes). Thanks for playing!
Digiscoped with Panasonic DMC-LX5 | Nikon FieldScope III | 30XWA | hand-held (no adapter)