[3] The nominate black-capped gnatcatcher is found in western Mexico from central Sinaloa south to Colima.

P. n. restricta is found mostly in western Mexico from eastern Sonora south to northern Sinaloa.

It has occasionally nested just across the U.S. border in the Madrean sky islands area of southernmost Arizona.

They forage actively in trees or shrubs, gleaning foliage and sometimes sallying to catch insects.

[3] The black-capped gnatcatcher's breeding season spans from March to June, with the last fledging in July.

[1] However, "Both races [are] restricted to ecoregions considered to be at serious risk due to agriculture and cattle grazing.