Thorn-tailed Rayadito (Aphrastura spinicauda) [XC380810]
by Fernando Medrano from Tranque Pitama, Chile (call, song)
Thorn-tailed Rayadito (Aphrastura spinicauda) [XC47577]
by Niels Krabbe from Santa Cruz: Parque Nacional Los Glaciares, Lago Roca, Argentina (alarm call)
Subspecies
Affinities of genus uncertain; plumage features suggest possible relationship to Phleocryptes and to sympatric Pygarrhichas. Close to, and perhaps ancestor of, Masafuera Rayadito (Aphrastura masafucrae). Validity of subspecies bullocki, described from only two specimens, perhaps requires reconfirmation. Also, individuals with ochraceous underparts, thus resembling fulva, evidently occur throughout near-shore Chilean islands, suggesting that this ventral pattern may appear independently in insular populations as response to more humid conditions (Gloger's Rule). In addition, population on Diego Ramírez I apparently differs morphologically from typical nominate form. Further study needed in order to clarify geographical limits and validity of subspecies.
The following 3 subspecies are recognised:
spinicauda (Gmelin, 1789) - Central and southern Chile (southern from southern Coquimbo) and extreme western Argentina (southern from Neuquén) south to Tierra del Fuego, Staten I and Diego Ramírez I. Also Falkland Is.
bullocki Chapman, 1934 - Mocha I, off south-central Chile.
fulva Angelini, 1905 - Chiloé I, off south-central Chile.