Noteworthy ornithological records from Rondonia, Brazil, including a first country record, comments on austral migration, life history, taxonomy and distribution, with relevant data from neighbouring states, and a first record for Bolivia

摘要

Located in the south-west of Brazil's immense Amazon region is the state of Rondonia. Rivers play a major role in the state's geography with the rio Madeira dissecting the western section as it flows north-east into the Amazon. Furthermore, the borders with Bolivia are defined by the rios Mamore, Guapore and Branco. The state's largest river, the Madeira, acts as a major barrier to many species of birds, animals and plants, which occur on only one side (Haffer 1992). Further east is the rio Tapajos,flowing north-east and forming another major physical barrier to species distribution. The area of land between these two major Amazon tributaries is known as the 'Rondonian area of endemism', and contains many unique bird taxa (Haffer 1974, Cracraft 1985). The Rondonian endemic centre encompasses almost all of Rondonia, with the exception of the extreme west, on the left bank of the rio Madeira, bordering Amazonas and Acre. The presence of this rich endemic centre makes Rondonia of very high conservation importance, due not only to the large number of endemics but also the extremely high indices of deforestation (Fearnside 1987, 1989). Thus the fauna and flora of Rondonia are some of the most threatened within all of Brazilian Amazonia.