In terms of size, it has a length of between 34 and 35 cm and a wingspan of between 52 and 58 cm. Its most notable characteristics, particularly its plumage, include blue feathers with stripes contrasting with the brown color of the rest of its body, as well as black, mustache-like stripes under its eyes and black stripes on its head. It has a rather loud and hoarse call. It can also imitate the sounds of other birds, demonstrating its intelligence, typical of corvids.

It is omnivorous, feeding on acorns, seeds, fruits, insects, and sometimes eggs and chicks of other birds. It stores acorns for consumption in the autumn and winter. It reproduces between April and July. The nest is built in trees between 3 and 10 meters high. The female lays between 4 and 6 eggs and incubates them for 16 to 19 days. After hatching, both parents feed the chicks for 21 to 23 days, after which they are ready to leave the nest, although they continue to be fed by their parents for a few more weeks.