Status and Identification of Fox Sparrow Subspecies in the Central Valley of California

The Fox Sparrow (Passerella iliaca) is a regular winter resident of thickets and riparian corridors in the Central Valley. It is a highly variable species, with at least thirteen subspecies divided into four groups. A recent DNA analysis suggested that the four groups are well-defined and distinct from each other, thus meriting species status (Zink and Weckstein 2003). The American Ornithological Union, however, has yet to act on this due to apparent intergrades between groups. While all four of the groups and most of the subspecies occur in the Central Valley, their status and field identification criteria are not widely understood.