The Yellow-billed Magpie (Pica nutalli) is a large bird in the crow family that is restricted to the U.S. state of California. It inhabits the Central Valley and the adjacent chaparral foothills and mountains. Apart from its having a yellow bill and a yellow streak around the eye, it is virtually identical to the black-billed magpie (Pica hudsonia) found in much of the rest of North America. The scientific name commemorates the English naturalist Thomas Nuttall.
mtDNA sequence analysis indicates a close relationship between the yellow-billed magpie and the black-billed magpie, rather than between the outwardly very similar black-billed and European magpies (P. pica); the two American forms could be considered as one species.
Combining fossil evidence[3] and paleo-biogeographical considerations with the molecular data indicates that the yellow-billed magpie's ancestors became isolated in California quite soon after the ancestral magpies colonized North America (which probably happened some 3–4 mya) due to early ice ages and the ongoing uplift of the Sierra Nevada, but that during interglacials there occurred some gene flow between the yellow- and black-billed magpies until reproductive isolation was fully achieved in the Pleistocene.
The yellow-billed magpie is gregarious and roosts communally. There may be a cluster of communal roosts in one general area made up of a central roost containing many birds and several outlying roosts with fewer. Yellow-billed magpie flocks are known to engage in funeral-like behavior for their dead.
These omnivorous birds forage on the ground, mainly eating insects, especially grasshoppers, but also carrion, acorns and fruit in fall and winter. They are attracted to recently butchered carcasses on farms and ranches. They pick through garbage at landfills and dumping sites, and sometimes hunt rodents.
This bird is extremely susceptible to West Nile virus. Between 2004 and 2006 it is estimated that 50% of all yellow-billed magpies died of the virus. Because the bird tends to roost near water bodies such as rivers, it is often exposed to mosquitoes. The IUCN classifies the bird as a near threatened species. The Nature Conservancy places it in the vulnerable category. Besides West Nile Virus, threats include loss of habitat and rodent poison. The bird has a limited area of distribution but is widespread throughout the area and still common in many places.
These photographs were taken at the Alisal Ranch, Solvang, CA.