The black-throated magpie-jay is a strikingly long-tailed magpie-jay of northwestern Mexico.
This species is 58.5 to 76.5 cm (23 to 30 inches) long, more than half of which is the tail, and weight is
225-251 grams (8-9 oz.). Only a very few corvids, including the black-billed magpie, the red-billed blue
magpie and the closely related white-throated magpie-jay, have a comparable tail length. The upperparts are
blue with white tips to the tail feathers; the underparts are white. The bill, legs, head, and conspicuous
crest are black except for a pale blue crescent over the eyes and a patch under the eye. In juveniles, the
crest has a white tip and the patch below the eye is smaller and darker blue than in adults. In most birds,
the throat and chest are also black, but some in the southern part of the range have various amounts of white
The calls are varied, loud, raucous, sometimes parrot-like.
Range and habitat
This species occurs in pairs or small groups in woodland, except for humid woodland, and partially open
areas on the Pacific Slope of Mexico from southern Sonora south to Jalisco and northwestern Colima, for a
total of 160,000 km2. As of 1993 there was some evidence of a population decline.
The species has become established in southern San Diego County (2013), especially in the Tijuana River
Valley. The birds are presumably descendants of escapees from nearby Tijuana, Baja California, where the
trade in birds is unregulated.
The diet is the omnivorous one typical of the crow family.
The nest is also typical of the family: a big cup of sticks lined with softer material. The female lays 3
to 7 whitish eggs with brown and gray spots.
This species interbreeds with the white-throated magpie-jay in Jalisco and Colima, where intermediate birds
are common. It has been considered a subspecies of the white-throated magpie-jay, Calocitta formosa colliei.
The binomial commemorates the Scottish naturalist Alexander Collie.