A few days ago the paper appeared in the online list of Ecological Informatics:

• Acevedo, M.A., Carlos J. Corrada-Bravo, Héctor Corrada-Bravo, Luis J. Villanueva-Rivera, and T. Mitchell Aide. 2009. Automated classification of bird and amphibian calls using machine learning: A comparison of methods. Ecological Informatics. doi:10.1016/j.ecoinf.2009.06.005

Abstract below the fold.