Revista Brasileira de Ornitologia, 20(4), 393-442 ARTIGO/ARTICLE Dezembro de 2012 / December 2012 Birds of the Brazilian state of Acre: diversity, zoogeography, and conservation Edson Guilherme1 1 Universidade Federal do Acre, Museu Universitário, Laboratório de Ornitologia. Campus Universitário - BR 364, Km 04, Distrito industrial, Rio Branco - Acre, Brazil. CEP: 69915-900. E-mail:
[email protected]. Received 12 March 2012. Accepted 27 July 2012. ABSTRACT: The Brazilian state of Acre borders Peru and Bolivia to the west and south, and the Brazilian states of Amazonas and Rondônia to the north and east, respectively. The state is located within the lowlands of the western Amazon basin, adjacent to the foothills of the Andes, within a “megadiverse” region of the Brazilian Amazon basin. Despite its diversity, the region is still only poorly known in scientific terms, and is considered to be a priority for future biological surveys. Given this situation, the present study aims to contribute to the scientific knowledge of the avian fauna of southwestern Amazonia, by evaluating the following questions – (a) how many and which bird species occur in the state of Acre?; (b) how are these species distributed within the state?; and (c) what are the priority areas for new ornithological surveys within the state of Acre? My methodological procedures included (a) a wide literature search; (b) two years of field surveys, including observation records and the collection of voucher specimens; (c) map the distribution of avian taxa within the two main interfluvial regions (east and west of the Purus River) of the state; and (d) the identification of contact and possible hybridization zones, based on the distribution of parapatric sister taxa.