Location in Oregon
Blue is Winter range - Red is Summer range

Bobolink

Dolichonyx oryzivorus - Locally common in hayfields and fall migration in large flocks near marshes. Spring male is only North American land bird dark below, light above. Female and fall males resemble large sparrows, but have buffy crown stripes, buffy breast, and narrow pointed tail feathers. Song, a long, loud, and bubbling, 5 to 15 per minute.