Currently we do not know whether the strength of these effects
on song would be enough to distort its potentially rich phylogenetic
information, because the variation in song explained by sexual
selection and by these ecological effects is generally small
compared to the range of differences between species (Garamszegi
& Møller 2004; Boncoraglio & Saino 2007; Cardoso & Price 2010).
Also, although phenotypic traits such as sexual ornaments and
signals are no longer important for taxonomy, findings of high
phylogenetic signal in birdsong make the issue of its taxonomic
value recurrent in the literature (Irwin 1996; Price & Lanyon 2004).
Here we tested for ecological effects on song evolution and assess
how they affect its phylogenetic information, using a real case of
flawed taxonomy.