Mexican Jay, Aphelocoma wollweberi arizonae

Mexican Jay, Aphelocoma wollweberi arizonae. Photograph taken within a residential community in Hereford, Arizona, April 2010. Photograph and identification courtesy of Bob Behrstock, Sierra Vista, Arizona (naturewideimages.com).

Mexican Jay, Aphelocoma wollweberi arizonae. Photograph taken within the Reserva Monte Mojino, Alamos, Sonora, April 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora. 

The Mexican Jay, Aphelocoma wollweberi arizonae, is one of five subspecies of Mexican Jay, all five of which are found in Mexico. They are a member of the Corvidae Family of Crows, Jays and Magpies, which has one hundred twenty-eight global members placed in twenty-three genera, and is one of seven global species of the Aphelocoma Genus. They are also known as the Gray-breasted Jay and in Mexico as chara pechigrís.

The Mexican Jay is mid-sized in stature. They have an overall blue coloration that varies by location, being grayish-blue above, and transitioning to off white below. Most have a black bill, with birds from some regions having lighter bills, their iris is brown, and their legs and feet are black.

The Mexican Jay is found within pine-oak juniper woodlands. They are omnivores that consume arthropods, lizards, and seasonal acorns, berries, and pine nuts. The Mexican Jay is a highly social species that forms groups of five to twenty-five individuals and has a social organization that is one of the most complex known for birds. They live their entire life with their family members, very close to their birth site. Within each territory, one to four females may breed simultaneously and somewhat monogamously. The young are fed not only by their own parents but also by many other flock members, namely other breeders, failed breeders, and some nonbreeders. They have life spans of up to twenty years.

The Mexican Jay is a year-round, non-migratory resident of the mountains of central and northern Mexico within the states of southeast Sonora south to Durango, Zacatecas, eastern Nayarit, northern Jalisco and from southern Nuevo León and San Luis Potosí south to central Hidalgo. The arizonae subspecies is found in northern Sonora and northwest Chihuahua.

The Mexican Jay is similar to the Scrub Jays (possess a white necklace and eyeline with brown backs) and the Pinyon Jay, Gymnorhinus cyanocephalus (gray breast, longer tail, shorter, less pointed bill).

From a conservation perspective the Mexican Jay is currently considered to be of Least Concern with stable, widely-distributed populations. They are reasonably tolerant of human development, but their long-term viability is threated by human habitat destruction. They have been used in laboratory studies, comparing spatial memory in seed-caching corvids. Their sedentary ways make also make them amenable to studies of genetic differentiation at both large and small spatial scales.