Savannah Sparrow (Passerculus sandwichensis [sandwichensis Group]) 8 April 2012, Chico Oxidation Ponds, Chico, Butte County, CA Photos © 2012 Joseph Morlan
This highly variable, but distinctive species is a migrant and winter visitor in this area. It breeds along the California coast and also in the Great Basin but skips over most of interior California except during the winter and migration. The overall grayish color and lack of yellow on the supercilium suggests that these may be P. s. nevadensis which breeds in the Great Basin, but precise subspecific identification is speculative outside the breeding season because of the high degree of individual variation within subspecies.
The characteristic short primary projection and short, notched tail are evident in the lower image. Savannah Sparrow is the only member of the genus Passerculus. The upper phto was taken from a blind intended for wildlife observation and photography. However it was tricky to get the scope angled through the observation slit.
I left the EXIF information embedded in these images for those who might want technical details.
Digiscoped with Panasonic DMC-LX5 | Nikon FieldScope III | 30XWA | hand-held (no adapter)