Cinnamon-rumped Seedeater

Cinnamon-rumped Seedeater, Sporophila torqueola

Cinnamon-rumped Seedeater, Sporophila torqueola atriceps, Male. Photograph taken in Huatabampo, Sonora, April 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

Cinnamon-rumped Seedeater, Sporophila torqueola atriceps, Breeding Male. Photograph taken within a residential community in Alamos, Sonora, December 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

Cinnamon-rumped Seedeater, Sporophila torqueola atriceps, Female. Photograph taken within a residential community in Alamos, Sonora, December 2018. Photograph and identification courtesy of David F Smith, Alamos, Sonora.

Background and Identification

The Cinnamon-rumped Seedeater, Sporophila torqueola atriceps, is one of two subspecies of Cinnamon-rumped Seedeater, both found in Mexico. They are a member of the large Thraupidae Family of Tanagers and Allies, which has three hundred eighty-one individual species placed into one hundred seven genera, and one of forty-one global species of the Sporophila Genus. They are found in pairs or flocks of several hundred individuals during non-breeding season. They have life spans of up to twelve years. The Cinnamon-rumped Seedeater has been poorly studied and very little has been documented about their biology and behavioral patterns. They are known in Mexico as Semillero Torcaz.

The Cinnamon-rumped Seedeater is small in stature. This species is sexually monomorphic, except in the breeding season. Sexually monomorphic species have similar size and plumage, regardless of sex. It can be hard to distinguish sexually monomorphic species males from females in the field. During winter months (nonbreeding), males and females have identical plumage. Both sexes are buffy brown and unstreaked above with pale cinnamon underparts. Individuals are darker on the breast and flanks with a pale creamy chin, belly, and vent. Females sometimes have more grey to olive underparts, which can aid in identification. Breeding males develop white plumage on their throats and a dark stripe around the throat. The bills, iris, and legs of both sexes are black.

Habitat and Geographical Range

The Cinnamon-rumped Seedeater is found primarily in grassy and weedy fields, agricultural lands, pastures, moist savanna, and beach scrub. They feed on grass seeds supplemented by berries and insects in these areas.

The Cinnamon-rumped Seedeater is ENDEMIC to Mexico and found in Baja California Sur, and within the Pacific Slope from southern Sonora south to Oaxaca. The atriceps subspecies are found within the Pacific lowlands of Baja California Sur and from southern Sonora to western Durango and south to Nayarit and northern Jalisco at elevations up to 2,000 m (6,600 feet). They are non-migratory and year-round residents.

Common Misidentifications

Two other species in the genus Sporophila overlap geographically with the Cinnamon-rumped Seedeater and could be misidentified. The Ruddy-breasted Seedeater, Sporophila minuta, and the Variable Seedeater, Sporophila corvina. The Ruddy-breasted Seedeater is a smaller bird, with a paler bill. Wing-bars are absent in this species and two-toned plumage is displayed, grey above and ruddy (chestnut-colored) below. The Variable Seedeater has almost entirely black plumage in male individuals, and females are more olive-colored than female Cinnamon-rumped Seedeaters.

Conservation Perspective

From a conservation perspective the Cinnamon-rumped Seedeater is currently considered to be of Least Concern with stable, widely distributed populations. Their colonization in Baja California Sur is new and believed to be via human-induced introduction.