This genus belongs to the group of New World (or "blue") jays—possibly a distinct subfamily–which is not closely related to other jays, magpies or treepies.

They are believed to have evolved in the Pleistocene, and the Florida scrub jay is known to have been recognizably distinct and present in its current range for at least two million years.

In any case, the data of Rice et al. (2003)[5] suggests – albeit also with very low confidence – that the Mexican jay comprises two clades which might constitute two separate species.

However, far too few individuals have been sampled to say anything definite on that matter, except that the lineages – if they indeed exist – do not correspond to the geographical pattern of intraspecific variation (see species article for more).

They are most successful in areas that contain large quantities of oak shrubs that average 3.28-6.56 feet (1-2 meters).Diet: Insects, frogs, toads, lizards, mice, bird eggs, and acorns.

The breast is also white or grey-white and the back is a grey-brown contrasting with the bright blue tail and wings in most species.

These birds can also be omnivorous; their diet can include insects, eggs and nestlings, small frogs, mice, and reptiles.

A positive correlation was found between increased prolactin levels during the breeding period and helping behavior in non-breeding Aphelocoma jays.

[7] This suggests that helper birds do not simply respond to the calls of the young, but begin to show parental behavior even before the chicks hatch.