- Crows, Ravens, Jays, Magpies
This striking bird is endemic to the Central Valley and Coast Ranges of California. A close relative of the Black-billed Magpie, it prefers oak savannah woodland and other areas with large trees scattered across wide open spaces. Habitat loss and exposure to poison from ground squirrel control efforts have led to population declines over parts of its historical range.
Closely resembles Black-billed Magpie, with black head and chest, white shoulders and belly, iridescent blue wings, and long tapered black tail. Bill is bright yellow. Bare skin behind eyes is also yellow, though not always clearly visible. Males are slightly larger than females; otherwise, sexes alike.
Distribution and Population Trends
Nonmigratory. Endemic to California, west of Sierra Nevada. Range includes Sacramento and San Joaquin valley floors and foothills, and valleys of Coast Ranges from San Francisco Bay south to Santa Barbara County. In some areas, the species coexists with dense human settlement, but in other parts of the bird's former range, populations have declined or vanished in apparent response to development of housing or agriculture. Breeding Bird Survey trend analysis shows no change in numbers from 1966-2001.
Inhabits open country with tall trees. Nests high in trees, predominantly in valley oaks and coast live oaks. Nests are very large (almost 1 meter across), made of sticks and mud. Egg-laying usually begins in late April; clutches generally have 6 or 7 eggs. Forages mostly on the ground in grassland, agricultural fields, pastures, and barnyards, taking a variety of insects and occasionally, small mammals. Yellow-billed Magpies are highly social, foraging and roosting together often in large numbers. They are often seen aggressively mobbing predators or other perceived threats, including humans.
Habitat loss has already extirpated the species from parts of its historical range. Poison used for extermination of ground squirrels has been strongly implicated in the catastrophic decline of one California population; declines from the 1800s are also linked to pest and predator control.
Preservation of oak savannah woodland habitat is necessary for the continued persistence of major populations of this species. Poisoning of ground squirrels within the species' range should be avoided.
What Can You Do?
Audubon California's Important Bird Area program is a vital tool for the conservation of Yellow-billed Magpie as well as other species. To learn more about the Important Bird Areas program and how you can help, visit: http://www.audubon.org/bird/iba/.
Support local land trusts, government agencies, and other organizations working to preserve oak -savannah habitat in your area. Contact the California Important Bird Areas coordinator (http://www.audubon.org/bird/iba/state_coords.html) to find out if there are sites in your area important for Yellow-billed Magpie that need increased protection.
Volunteers are crucial to the success of programs that monitor the long-term status of wintering populations of Yellow-billed Magpie and other bird species. Audubon's Christmas Bird Count (CBC) is one of the longest-running citizen-science monitoring programs in the world and has helped to follow changes in the numbers and distribution of Yellow-billed Magpie. To learn more about the CBC and how you can participate, visit: http://www.audubon.org/bird/cbc
Information on where Yellow-billed Magpie occurs and in what numbers is vital to conserving the species. Help in monitoring this and other species by reporting your sightings to eBird. A project of Audubon and the Cornell Lab of Ornithology, eBird is the world's first comprehensive on-line bird monitoring program: http://www.audubon.org/bird/ebird/index.html
Reynolds, M.D. 199. Yellow-billed Magpie (Pica nuttalli). In The Birds of North America, No. 180 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, and the American Ornithologists' Union, Washington, DC.