MOLECULAR PHYLOGENY OF SOUTH-AMERICAN SCREECH-OWLS OF THE OTUS-ATRICAPILLUS COMPLEX (AVES, STRIGIDAE) INFERRED FROM NUCLEOTIDE-SEQUENCES OFTHE MITOCHONDRIAL CYTOCHROME-B GENE

The cytochrome b gene of 6 South American screech owls of the genus Ot us (O. choliba, O. atricapillus O. usta, O. sanctaecatarinae, O. guate malae, and O. hoyi) and two Old World species (Otus scops and Otus leu cotis) was amplified by polymerase chain reaction (PCR) and partially sequenced (300 nucleotides). Otus atricapillus, O. guatemalae O. hoyi and O. sanctaecatarinae which are morphologically very similar, have b een treated as belonging to a single species, A. atricapillus (Sibley and Monroe, 1990). Nucleotide sequences differ substantially between t hese taxa (6.3 to 8.8% nucleotide substitutions) indicating that they represent well established and distinct species which had been implica ted already from ecological and bioacoustical analyses (Konig, 1991, 1 994). The importance of vocal and ecological characters for the taxono my of nocturnal birds is thus confirmed by our molecular analysis. Phy logenetic relationships were reconstructed between Old and New World o wls using character state (''maximum parsimony''; PAUP 3.1.1) and dist ance matrix methods (neighbour-joining; MEGA).