The Transvolcanic jay (Aphelocoma ultramarina ) is a medium-large (~120 g) passerine bird similar in size to most other jays, with a blue head, blue-gray mantle, blue wings and tail, gray breast and underparts. The sexes are morphologically similar, and juveniles differ only in having less blue coloration. The iris is brown and legs are black. It is most readily distinguished by the plain (unstreaked) throat and breast, and the mantle contrasting less with the head and wings.