Systematics

Two color morphs of Brown Jay are the plain-tailed (or brown-tailed) and white-tipped morphs; the latter was once considered a separate species, P. mexicanus (Selander 1959, dos Anjos 2009). Morphs are distinguishable based on the color of retrices. Plain-tailed morphs have an entirely brown tail while white-tipped morphs have white tips on retrices 2-6 (the central pair of rectrices are entirely brown). Although similar in habitat requirements and preference, the plain-tailed morph generally occurs in more mesic habitat on the eastern coast of Mexico west of the Yucatan peninsula and the white-tipped morph occurs in more arid habitat from central Mexico and the Yucatan peninsula to Panama. A polymorphic zone is found in central Mexico (Selander 1959). The different morphs frequently pair and reproduce and show identical behaviors (Selander 1959).

Three subspecies are recognized:

palliatus van Rossem 1934, occupying the Lower Rio Grande Valley in southern Texas and eastern Mexico south to Puebla and northern Veracruz.

This subspecies occurs only in the plain-tailed morph.

morio (Wagler 1829), distributed from southeast Mexico from the coastal plain of central Veracruz south, except in the Yucatan Peninsula, to western Panama; also occurs on the Pacific slope of Costa Rica

Both plain- and white tailed morphs occur from Veracruz south to northeastern Chiapas; populations south of this region all are white tailed. This subspecies is darker, in the plain tailed morph, than palliatus (Phillips 1986). The white tailed has a duller, less clearly whitish breast does vociferus, and the tibial feathers are "more or less tinged with fuscous distally" (Phillips 1986).

vociferans (S. Cabot 1943), which occurs in the northern Yucatan peninsula

Tibial feathers are white; lower breast white, contrasting sharply with the dark upper breast (Phillips 1986). Occurs only in the white tailed morph.

First described by Wagler (1829) and given the name Pica morio. Later, Ruppell (1837) described the genus Psilorhinus, which consisted of the Brown Jay (P. morio) and the White-tipped Brown Jay (P. mexicanus). P. mexicanus was subsequently subsumed into P. morio and considered a separate phenotypic morph (Selander 1959).

Generic placement of the Brown Jay has been subject of debate for many years (Saunders and Edwards 2000). Previously lumped with Cyanocorax (Hardy 1969, AOU 1983, AOU 1998), but in 2010 Brown Jay was returned to the monotypic genus Psilorhinus on the basis of genetic and morphological characters (Chesser et al. 2010). Based on osteological characters, Psilorhinus was placed as sister to Calocitta (magpie-jays) and closely related to Cyanocorax violaceus (Violaceous Jay), C. caeruleus (Azure Jay), and C. cyanomelas (Purplish Jay) (Hope 1989). More recent phylogenetic analysis based on the entire mitochondrial control region suggests that despite morphological similarities with species of the genus Cyanocorax, Brown Jay lies outside of Cyanocorax and is likely sister to Calocitta (Saunders and Edwards 2000). Most recent phylogenetic treatments based on nuclear and mitochondrial genes supported the monophyly of Psilorhinus, Calocitta, Cyanocorax violaceus, C. caeruleus, C. cyanomelas, and C. cristatellus (Curl-crested Jay), however the placement of Psilorhinus within this clade was unstable (Bonaccorso et al. 2010).

The only known example of a hybridization in Brown Jays is a record of a Brown Jay x White-throated Magpie-Jay (Calocitta formosa) hybrid from east-central Chiapas, Mexico (Pitelka et al. 1956).