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Observations on the Andean-Patagonian Component of Southeastern Brazil's Avifauna

1985; Issue: 36 Linguagem: Inglês

10.2307/40168284

1941-2282

Helmut Sick,

Ecology and Vegetation Dynamics Studies

Several birds typical of southeastern Brazil's isolated and cold mountains have most probably been derived from Andean/Patagonian ancestors following Pleistocene glaciation. Typical species endemic to that area include Itatiaia Spinetail (Schizoeaca moreirae), Long-tailed Cinclodes (Cinclodes pabsti), and Mousecolored Tapaculo (Scytalopus speluncae). Uniquely among Andean-Patagonian derivatives, Band-winged Nightjar (Caprimulgus longirostris) has also colonized lowlands, even reaching tropical, urban Rio de Janeiro. Secondary radiation has led to at least one species of Andean origin (Brasilia Tapaculo, Scytalopus novacapitalis) colonizing the central Brazil Plateau, apparently having followed the inland movement of coastal forests. Extension southward of Amazonian heat and northward of Patagonian aridity are advanced in explanation for the rupture of a formerly continuous band of vegetation linking the Andes and southeastern Brazil, with resulting isolation and speciation of landbirds. RESUMEN. Varias aves tipicas de las montanas aisladas y frias del sureste de Brasil han derivado muy probablemente de ancestros andino-patagonicos luego de las glaciaciones del pleistocene Especies endemicas tipicas de esa area incluyen Schizoeaca moreirae, Cinclodes pabsti, y Scytalopus speluncae. La chotacabra sen-ana (Caprimulgus longirostris) es unica entre los descendientes andinopatag6nicos, ya que tambien ha colonizado las tierras bajas e incluso ha llegado a las areas urbanas y tropicales en Rio de Janeiro. La radiation secundaria ha hecho que al menos una especie de origen andino (Scytalopus novacapitalis) colonice la meseta central de Brasil, aparentemente habiendo seguido las extensiones tierra adentro del bosque atlantico. La extensidn del calor amaz6nico hacia el sur y de la aridez patag6nica hacia el norte brindan una hipdtesis para explicar la ruptura de una banda de vegetaci6n que en el pasado era continua y enlazaba los Andes con el sur de Brasil, dando como resultado la aislacion y especiacidn de aves terrestres. The Itatiaia Highlands of southeastern Brazil (Fig. 1) were recognized early in the 20th century as having a peculiar flora composed largely of endemics whose closest relatives were in the Bolivian Andes (Dusen 1903). Shortly thereafter, Miranda Ribeiro (1906) extended the analysis to the area's fauna, confirming its Andean affinities. He noted among other observations that the nearest relatives of certain catfishes (Siluroidei) and some birds were not in Brazil but in the Andes, a conclusion later reached for frogs and butterflies as well (Lutz 1951; Ebert 1960). In the present paper I offer observations on the taxonomic affinities of birds that occur generally in southeastern Brazil.