The Island Scrub-Jay is a large, crestless, and long-tailed blue-and-grayish-white jay. There are no other jays or similar species in its geographic range. Its crown, nape, sides of breast, wings, upper tail-coverts, and tail are a uniform dull ultramarine blue. The auricular and malar regions are blackish with variably extensive dark-blue tinge below and behind eye. It is distinguished from the Western Scrub-Jays of nearby California mainland by larger size, disproportionately long bill, broad skull, and long tarsi.

References cited in Species Profile

• Atwood, J. L. 1978. Breeding biology of the Santa Cruz Island Scrub Jay, Aphelocoma coerulescens insularis. Master's Thesis. California State Univ. Long Beach.
• Beck, R. H. 1899. Nesting of the Santa Cruz Jay. Condor 1:6.
• Bent, A. C. 1946. Life histories of North American jays, crows, and titmice. U.S. Natl. Mus. Bull. 191
• Curry, Robert L. and Kathleen Semple Delaney. 2002. Island Scrub-Jay (Aphelocoma insularis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online.
• Curry, R. L., A. T. Peterson, and T. A. Langen. 2002. Western Scrub-Jay (Aphelocoma californica). in The birds of North America, no. 712. (Poole, A. and F. Gill, Eds.) The Birds of North America, Inc. Philadelphia, PA.
• Dawson, W. L. 1920. The case of the Santa Cruz Island Jay, Aphelocoma insularis Hensh. J. Mus. Comp. Ool. 1:26-29.
• Dawson, W. L. 1923. The birds of California. South Moulton, Los Angeles.
• Isitt, J. J. 1989. Evolution of the Scrub Jay, Aphelocoma coerulescens in the western United States. Master's Thesis. California State Univ. Long Beach.
• Junak, S., T. Ayers, R. Scott, D. Wilken, and D. Young. 1995. A flora of Santa Cruz Island. Santa Barbara Botanic Garden and California Native Plant Soc. Santa Barbara, CA.
• Pitelka, F. A. 1951. Speciation and ecological distribution of American jays of the genus Aphelocoma. Univ. of California Publ. Zool. 50:195-464.
• Sillett, T.S., R.B. Chandler, J.A. Royle, M. Kery, and S.A. Morrison. 2012. Hierarchal distance-sampling models to estimate population size and habitat abundance of an island endemic. Ecological Applications 22:1997-2006.
• Van Vuren, D. and B. E. Coblentz. 1987. Some ecological effects of feral sheep on Santa Cruz Island, California, USA. Biol. Conserv. 41:253-268.