The Western Scrub Jay is a medium-sized bird, approximately 27–31 cm (11.5 in) in length (including its tail), with a 39 cm (15 in) wingspan, and about 80g in weight. Coastal Pacific birds tend to be brighter in coloration than those of the interior, but all are patterned in blue, white and gray, though none as uniform in color as the related Mexican Jay. In general, this species has a blue head, wings, and tail, a gray-brown back, and grayish underparts. The throat is whitish with a blue necklace. The call is described as "harsh and scratchy".