Black-chested Sparrow, Peucaea humeralis
Black-chested Sparrow, Peucaea humeralis. Photograph taken Xochicalco, Moreles, March 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora.
Background and Identification
The Black-chested Sparrow, Peucaea humeralis, is a member of the Passerellidae Family of New World Sparrows, which has one hundred thirty-two members placed in thirty genera and is one of eight global species of the Peucaea Genus. They are generally found as single individuals or in pairs, as they usually mate for life. Primarily, the Black-chested sparrow consumes insects including larvae, grasshoppers, termites, seeds, and fruits. This species has been poorly studied and very limited information about their behavioral patterns and biology has been documented. They are known in Mexico as Zacatonero Pechinegro and Zacatonero Pecho Negro.
The Black-chested Sparrow is sparrow-shaped and medium size in stature. Both sexes are about 15.0 cm (5.9 inches) to 15.5 cm (6.1 inches) in length and weigh between 18 g (0.63 oz) to 27 g (0.95 oz). The sexes are similar in appearance, known as sexual monomorphism. Their bill has a black upper mandible and blue-gray lower mandible, their iris is brown, and their legs are pale pink. They have a blackish-gray head with a white mustache and loral streaks. Their underparts are white with a broad black breast band and a rufous back. Rofous refers to a rusty orange and red color combination.
Habitat and Geographical Range
The Black-chested Sparrow is found within the canopy of arid thorn forests and scrubby thickets at elevations up to 1,500 m (4,900 feet). They are sedentary permanent residents. They are generally found as single individuals or in pairs. They primarily consume insects including larvae, grasshoppers, termites, seeds, and fruits. The Black-chested Sparrow has been poorly studied and very limited information about their behavioral patterns and biology has been documented.
The Black-chested Sparrow is ENDEMIC to Mexico. They are primarily found on the Pacific Slope from west-central to south-central portions of the country from southern Jalisco and Colima east to Morales and Puebla, south to Guerrero, and southwest Oaxaca.
Common Misidentifications
The Black-chested Sparrow can sometimes be confused with other sparrow species that share similar habitats and geographic ranges. One potential look-alike is the Botterie’s Sparrow, Peucaea botterii, which also has a streaked back and similar size but lacks the distinctive black chest patch and has a more muted overall coloration. Another similar species is the Cassin’s Sparrow, Peucaea cassinii, which has a more uniformly brownish appearance and lacks the bold facial markings and black chest patch. Observing the distinctive black chest patch and facial markings of the Black-chested Sparrow can help differentiate it from these other species.
Conservation Status
From a conservation perspective, the Black-chested Sparrow is currently considered to be of Least Concern, with stable, widely distributed populations. This indicates that it is not at immediate risk of extinction. However, the species faces localized threats from habitat loss and degradation caused by agricultural expansion, urban development, and overgrazing by livestock.