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Red-shouldered Blackbird | Agelaius assimilis
Roodschoudertroepiaal | Mayito de ciénaga
The Red-shouldered Blackbird is a Cuban marsh bird long treated as a subspecies of Red-winged Blackbird Agelaius phoeniceus. On the basis of genetic studies, the different female plumage and its song, it is now regarded as a separate species. In Cuba it is called mayito de ciénaga.
Voice
Sings less often than Red-winged Blackbird. Male and female have similar songs and also duet, the male usually perched above the female. Also short, dry calls.
Recording: FREDERIC Lionel — CC BY-NC-SA 4.0 · converted to mono · xeno-canto
Identification
20–22 cm; the male is larger than the female. The male is glossy black with a red shoulder patch narrowly bordered yellow, as in Red-winged Blackbird. The female, unlike that of Red-winged Blackbird, is all black, unstreaked and with no or hardly any red on the shoulder. Juveniles are duller, browner black. The bill is pointed and black.
Confusion species
Tawny-shouldered Blackbird Agelaius humeralis has a tawny shoulder patch, is slightly smaller and lives in drier, open country. Cuban Blackbird Ptiloxena atroviolacea has a violet gloss and no coloured shoulder. Greater Antillean Grackle Quiscalus niger is larger, with a yellow eye and a long, keel-shaped tail. The male Shiny Cowbird Molothrus bonariensis has a purple gloss and a shorter, thicker bill; the female cowbird is brown, not black.
Habitat
Freshwater marshes with sawgrass, cattails and reeds, and the edges of adjacent rice fields and wet pastures. It is sedentary and rarely moves far from its breeding area. It eats insects and seeds. The nest is slung in marsh vegetation over water.
Where the bird is most at home, classified by the vegetation types of the Caribbean.
Range and movements
Only on Cuba, in the marshes of western Cuba, with the Zapata Peninsula as the main area, and on Isla de la Juventud. The total range is small, around 4,000 km². It does not occur outside Cuba.
- Resident
- Summer visitor (c. Oct–Mar)
- Winter visitor (c. Apr–Sep)
- Passage (Mar–Apr, Oct–Nov)
- dark = core range, pale = thinly spread
How and when to look
The best-known site is the Ciénaga de Zapata, where it can be found in reedbeds and along dykes and canals. Females are the best distinction from Red-winged Blackbird: all black rather than streaked brown.
Conservation status
Not threatened. The range is small, but the population is considered stable and no serious threats are known. As a marsh bird, however, the species depends on the conservation of the large marshes of western Cuba.
Scientific name
Agelaius assimilis | Lembeye, 1850
Lembeye described the species in 1850 and placed it straight away in the genus where it still stands. The genus Agelaius was introduced in 1816 by Vieillot. Agelaius is Greek, from agelaios 'gregarious, of a flock', after the birds feeding and roosting in large flocks. assimilis is Latin for 'similar', after its close resemblance to the Red-winged Blackbird (A. phoeniceus). The specimen the first description was based on came from Cuba.