Western Mexico from Sonora southern along Pacific slope to Chiapas, extending inland along Balsas drainage to south-western México; also southern Guatemala and El Salvador.
 
Population
Estimated population is 50,000 - 499,999 (2010).
Mexican Cacique (Cassiculus melanicterus) [XC351583]
by Frank Lambert from La Bajada, San Blas, Nayarit, Mexico (call)
Mexican Cacique (Cassiculus melanicterus) [XC614144]
by Manuel Grosselet from Ventanilla, Mazunte, Santa Mar\u00eda Tonameca, Oaxaca, Mexico (call)
Subspecies
No subspecies.
Often placed in genus Cacicus, but preliminary mitochondrial DNA data suggest an ancestral position within the cacique - oropendola clade. Is a rather distinctive species, geographically isolated from other caciques, with habitat preferences somewhat different from those of latter, and with nest resembling those of oropendolas. For all those reasons, placement in its own monotypic genus seems appropriate.