Estudo da evolução vocal de Furnariinae (Aves: Furnariidae)

Abstract

Birds vocalisation plays important roles in birds life and its evolution is shaped by several factors. The acoustic environment exerts considerable influences in the species vocal features, being that they tend to fit in the environments propagation properties in order to reach longer distances with least information loss. Vocal features are also shaped by the birds bodys and vocal structures mass, which constrain the capacity of reaching some sound frequencies and modulations. Moreover, geographic factors, such as latitude and altitude, and ecological factors, such as interspecific competition, can exert influences in birds vocal evolution. Various authors defend the importance of vocal characters for phylogenetic researches and some consider them evolutionarily more informative than the other sorts of data, especially regarding Subosines and non Passeres, whose song development is regarded as being innate. In this work, we studied the vocal evolution of the subfamily Furnariinae (family Furnariidae), a group of Suboscines. The familys evolution was affected by several geological, ecological and climatic processes that South America has undergone; notably the transformation of forests in grasslands. In this work we used continuous quantitative vocal data without discretisation. The newly described species Cinclodes espinhacensis Freitas, Chaves, Costa, Santos & Rodrigues, 2012 was used as a model to verify the viability of the use of this sort of data for accessing the species status. Our results show that the furnarines vocal characters exhibit much homoplasy and lack phylogenetic signal. The environments influences explain the groups vocal evolution better than the phylogenetic affinity. The groups phylogenetic tree based on these data did not exhibit congruence with Derryberry et al. (2012) molecular tree. Principal components analysis (PCA) show high overlapping rates amongst species. C. espinhacensis exhibited almost complete overlapping with its sister taxon, Cinclodes pabsti Sick, 1969