The Fox Sparrow is a large, chunky sparrow that is highly variable in appearance, depending on geographical region. It is dark and unstreaked on its back, varying from gray-brown, to dark brown, to rufous. The tail is typically redder than the back. The breast is heavily spotted, and the spots are shaped like chevrons that converge in a central spot on the breast. The head is not striped or streaked, the face is plain, and the lower mandible is yellow. The combination of the chevron markings, red tail, plain face, and yellow mandible are good field marks to use to identify the Fox Sparrow.