18 January 2006 - Salineno, Texas. This bird was originally recognized as a separate species and placed in the genus Parus. In 1983, it was lumped with the Tufted Titmouse (Parus bicolor) after careful studies by Dixon showed that it hybridized freely in a narrow but stable hybrid zone. The combined species (unfortunately named "Tufted Titmouse") was then moved from the genus Parus to Baeolophus 1997 in the 41st AOU supplement. It was then split again in 2002 when the AOU published the 43rd supplement to the Check-List: http://www.aou.org/checklist/Suppl43.pdf In that supplement, the AOU admitted that the two species hybridize freely in their contact zone, but cited recent studies showing that they are distinct genetically and vocally. Close the barn door! This ill-advised decision by the AOU does an end-run around the very core of the biological species concept which is based on reproductive compatibility. It paves the way for splitting on a massive scale. If genetic and vocal distinctions are all that are needed to split biological species, then every well defined subspecies with any unique vocalizations will qualify for full species status. We will be on our way to the quagmire of a disastrous phylogenetic species concept in which the number of recognized species will multiply faster than lemmings, and probably crash even faster.