Attenuated external primaries in doves: a comparative analysis of their functional significance

MAHLER, B.; TUBARO, P. L.

Cornell University, Ithaca, EEUU

Congreso; 117th Stated Meeting of the American Ornithologists Union; 1999

AOU

Sharp reduction of the inner web of the outer primary feather (hereafter referred to as attenuated primary) is present in more than one fifth of the 258 species of doves. Three hypotheses have been proposed to account for the functional significance of such a trait. First, the flight performance hypothesis suggests that attenuated feathers improve the flight performance in cluttered habitats, presumably because of an enhanced maneuverability. Second, the sexual selection hypothesis proposes that the trait evolved as a consequence of a sexual selection process based on female preferences upon the trait itself or the mechanical sounds it produces. Third, the signal hypothesis suggests that the mechanical sounds produced by attenuated feathers are of functional significance during communication in non-sexual contexts. These hypotheses were evaluated using a comparative analysis of phylogenetically independent contrasts. Only 6 species having attenuated feathers produce mechanical sounds during flight. Additionally, these species represent less than 21% of all dove species reported to produce that kind of sounds. Attenuated primaries were present in both sexes, irrespective of the sexual dimorphism in size or color. However, comparisons between pairs of related species showed that the presence of attenuated primaries is associated to the use of a more closed habitat. These results are compatible with the hypothesis suggesting that attenuated feathers are important for flight performance in cluttered habitats