Sharp-billed Canastero (Asthenes pyrrholeuca) [XC9734]
by Paul Smith from Reserva de Bi\u00f3sfera Laguna Oca, Formosa, Argentina (call)
Sharp-billed Canastero (Asthenes pyrrholeuca) [XC48989]
by Andrew Spencer from Reserva Otamendi, Campana, Buenos Aires, Argentina (call)
Subspecies
No obvious close relatives within genus. Short-billed Canastero (Asthenes baeri) suggested by some authors as possible sister-species on basis of plumage similarities.
Proposed Argentine subspecies leptasthenuroides (of which affinis is a synonym), described from Tucumán, and flavogularis, from Bahia Blanca (Buenos Aires) and Santa Cruz, represent seasonal plumage variation within subspecies sordida and nominate, respectively.
The following 4 subspecies are recognised:
sordida (Lesson, R, 1839) - Breeds central and southern Chile (Aconcagua south to Aisén, also sight records from Magallanes) and west-central Argentina (southern Mendoza, Neuquén, western Río Negro); some migrate north to north-western Argentina and southern Bolivia.
affinis Berlepsch, 1906 - Central Argentina and Chile. Winters to Bolivia and Paraguay.
pyrrholeuca (Vieillot, 1817) - Breeds central and southern Argentina (south-western Santiago del Estero, north-eastern Córdoba, and from southern La Pampa and south-western Buenos Aires south to central Santa Cruz; some migrate north to eastern and north-eastern Argentina and southern Paraguay.
flavogularis Gould, 1839 - Eastern and southern Argentina (Buenos Aires to Santa Cruz).