Historically, the Bufflehead (Bucephala albeola) has maintained a small, isolated breeding population in extreme northeastern California, restricted to parts of Butte, Lassen, Modoc, Plumas, Shasta, and Tehama counties (Figure 1, inset). Prior to 1996, there were no known breeding records from California south of Lake Almanor, Plumas County (San Miguel 1998). However, the Bufflehead occasionally breeds outside of its principal range, and extralimital records to the south have been recorded recently in Colorado (Ringelman and Kehmeier 1990), Minnesota (Mattsson 1986), South Dakota (Whitt 1999), and California (San Miguel 1998, Patten et al. 2003). San Miguel (1998) described three cases of extralimital breeding in California from 1996, and Patten et al. (2003) reported a brood found on the Salton Sea in 1999. These successful breeding efforts were discovered in a variety of habitats in Inyo, Los Angeles, Riverside, and Tulare counties, up to 850 km south of the species’ traditional breeding range (San Miguel 1998).