One of the few truly endemic bird species of California, the Yellow-billed Magpie is a conspicuous resident of open oak woodlands. Found primarily in the Central Valley, the southern Coast Ranges, and the foothills of the Sierra Nevada, this species generally nests in loose colonies of 3 to 30 pairs, although some nest solitarily. Its large, domed stick-nests are conspicuous features of nesting colonies.

Although this magpie has been the subject of several detailed studies of social behavior and ecology, gaps remain in our knowledge of its dispersal, vocal communication, development, evolutionary history, systematics, and relationships to the closely related Black-billed Magpie, now divided into polytypic Palearctic (Pica pica) and monotypic North American (P. hudsonia) forms. The Yellow-billed Magpie and North American Black-billed Magpie are more similar in vocalizations and social behavior than either is to Eurasian subspecies of Magpie. Coues ( Coues, E. (1903). Key to North American bird. Boston, MA: Dana Estes Co. Close Coues 1903) suggested that the persistence of the yellow-billed form in California was a “perpetuated accident.”

This species was named by John James Audubon in 1837 (as Corvus nutalli, [later nuttalli]) in honor of ornithologist Thomas Nuttall, who collected specimens near Santa Barbara, California.

Much of our knowledge concerning the behavior of this species comes from studies done at Hastings Reservation in central coastal California by Nicolas Verbeek ( Verbeek, N. A. M. (1972a). Comparison of displays of the Yellow-billed Magpie (Pica nuttalli) and other corvids. J. Ornithol. no. 113:295-313. Close Verbeek 1972a, Verbeek, N. A. M. (1972b). Daily and annual time budget of the Yellow-billed Magpie. Auk no. 89:567-582. Close Verbeek 1972b, Verbeek, N. A. M. (1973b). The exploitation system of the Yellow-billed Magpie. Univ. Calf. Publ. Zool. no. 99:1-58. Close Verbeek 1973b), Mark Reynolds ( Reynolds, M. D. (1990). The ecology of spacing behavior in the Yellow-billed Magpie Pica nuttalli. Phd Thesis, Univ. of California, Berkeley. Close Reynolds 1990), and Ginger Bolen ( Bolen, G. M. (1999). Extra-pair behavior in Yellow-billed Magpies (Pica nuttalli). Phd dissertation, University of California, Berkeley, CA. Close Bolen 1999, Bolen, G. M., S. I. Rothstein and C. H. Trost. (2000). Egg recognition in Yellow-billed and Black-billed Magpies in the absence of interspecific parasitism: Implications for parasite-host coevolution. Condor no. 102 (2):432-438. Close Bolen et al. 2000). Currently there is considerable conservation concern about this species related to its vulnerability to West Nile virus ( Crosbie, S. P., W. D. Koenig, W. K. Reisem, V. L. Kramer, L. Marcus, R. Carney, E. Pandolfino, G. M. Bolen, L. R. Crosbie, D. A. Bell and H. B. Ernest. (2008). Early impact of West Nile virus on the Yellow-billed Magpie (Pica nuttalli). Auk no. 125 (3):542-550. Close Crosbie et al. 2008).