Blue Bunting, Cyanocompsa parellina

Blue Bunting, Cyanocompsa parellina indigotica. Photograph taken in Copala, Sinaloa, February 2019. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

Background and Identification

The Blue Bunting, Cyanocompsa parellina indigotica, is one of three subspecies of Blue Bunting, all of which are found in Mexico. They are a member of the Cardinalidae Family of Cardinals and Allies, which has forty-nine members placed in fourteen genera, and the sole global species of the Cyanocompsa Genus. They are strikingly blue birds known for their vivid blue plumage and distinctive markings. In Mexico, they are known as Azulejito.

The Blue Bunting is a sexually dimorphic species. Males are slightly larger than females and have an overall dark blue coloration, with a light sky-blue forehead that transitions to a deeper blue at the base of the crown; they have an area in front of and behind the eye that is blackish, bright blue cheek patch, a bright ultramarine shoulders, and rump, with various shades of black and blue chins, throats, breast, belly, upperparts, and wings. Their bill is heavily rounded and blackish with a pale bluish-gray lower mandible, their iris is dark brown, and their legs and feet are blackish-brown. The females are a uniform dull brownish, with darker primaries and secondaries, a warmer and more rufescent on the belly. Males weight between 11 g (0.39 oz) and 24 g (0.85 oz) and are slightly larger; females weigh 9.8 g (0.35 oz) and 21 g (0.74 oz). Both sexes range from 13 cm (5.1 inches) to 14 cm (5.5 inches) in length. Juvenile males are generally grey-blue above and below, with much suffusion of dull brown, especially on the belly. Juvenile females look much like adult females.

Habitat and Geographical Range

The Blue Bunting is non-migratory and found in arid environments along forest edges, scrubby areas, and within the undergrowth of tall forests and thickets. They feed in pairs; however, the components of their diet have not been determined. They have been poorly studied and very little is known about their biology and behavioral patterns.

Geographically, the Blue Bunting is found within both the Atlantic and Pacific Slopes from Nuevo León south to Nicaragua and from central Sinaloa south to southwest Chiapas. The indigotica subspecies is found from central Sinaloa south to southern Oaxaca and the extreme southwestern Chiapas on the Pacific Slope at elevations up to 1,800 m (5,900 feet).

Common Misidentifications

The Blue Bunting is difficult to observe in the wild due to their dark coloration and secretive habits. The males are easy to identify; but the females can easily be confused with the Blue Seedeater, Amaurospiza concolor. This species has a much smaller bill than the blue bunting. Confusion can also occur when distinguishing the Blue Bunting from the Varied Bunting, Passerina versicolor. This species is duller in color and also has a smaller bill than the Blue Bunting.

Conservation Status

From a conservation perspective the Blue Bunting is currently considered to be of Least Concern with stable, widely distributed populations. They are believed to be capable of toleration of habitat modifications by human development, but changes in land use can reduce the number of suitable habitats, impacting their numbers. Conservation efforts for the Blue Bunting focus on protecting and managing forest habitats within their range. This includes preserving large tracts of tropical and subtropical forests, promoting sustainable agricultural practices, and implementing reforestation projects to restore degraded areas.