Livro de Resumos - Sociedade Brasileira de Ornitologia

variation, and morphometric data were analysed statistically to estimatediagnosis of the different subspecies and populations. Relationships wereanalysed with sequences of 575 base pairs from the Control Region of nineindividuals. The results of these analyses were combined with a review ofregional palaeonvironmental information, which allows for biogeographichypotheses to be put forward. The morphological studies identified thatmost of the variation of P. mixtus corresponds to clinal changes, but fourtaxonomic units exist in the group, based on morphology and distribution.The DNA sequences showed that the group represents a very recentradiation, and paraphyly of certain taxa was found possibly due toincomplete lineage sorting. Morphological variation was not related to thepattern of genetic relatedness. A scenario where the present morphologicalvariation and distribution are a likely result of climate and vegetational shiftsduring the late Pleistocene (since the last 20.000 years) is proposed. Thepattern will need to be analysed in other groups of lowland distributions,especially in relation to the effects of the tectonism of the Central Brazilianplateaux and the subsiding Chaco basin. This revision has implicationsfrom both conservation and biogeographic standpoints.________________________________________________R17Distribuição, status populacional e ecologia de Pyrrhura pfrimeri(Psittacidae).Carlos Bianchi, Marcelo Reis, Alexandre Portella, Flor Las-Casas, GustavoPéres e Fernanda Lucci.Diretoria de Conservação e Pesquisa, Jardim Zoológico de Brasília.Avenida das Nações Via L4 Sul, Brasília, DF. CEP 70.610-100. E-mail:bianchic@hotmail.comA ciganinha (Pyrrhura pfrimeri) é uma espécie endêmica doCerrado com distribuição restrita às formações de matas decíduas (secas)e semidecíduas do Brasil Central. Investigações sobre os limites dedistribuição (com a análise de mapas e verificações "in situ"), situaçãopopulacional (através de censos de linha e ponto; captura e coleta desangue para análises de DNA) e dados sobre a ecologia (observaçãodireta) têm sido realizadas na área de ocorrência da espécie. Os seguintes