Meeting Abstract

103.5  Wednesday, Jan. 7  Beyond the beak: wing shape variation in Darwins finches. VANHOOYDONCK, B*; HERREL, A; GABELA, A; PODOS, J; Univ. of Antwerp; Harvard University; Univ. Massachusetts, Amherst; Univ. Massachusetts, Amherst bieke.vanhooydonck@ua.ac.be

Wing design in birds is subject to a suite of interacting selective pressures. As different performance traits (e.g. manoevrability, aerodynamic efficiency, speed) are favoured in different ecological settings, a tight link between variation in wing morphology and variation in ecological parameters is generally expected. Here, we document aspects of variation in wing morphology in the medium ground finch (Geospiza fortis) on Isla Santa Cruz in the Galagos. We compare variation in body size, simple morphometric traits (body mass, wing chord, wing length, wing width and wing area) and functional traits (wing loading and wing aspect ratio) across years, among populations, and between sexes. Functional traits are found to covary across years with differences in climatic conditions (i.e. amount of rainfall), and to covary among populations with differences in habitat structure. Sexes differ in wing loading, with males having lower wing loadings than females. Lastly, in contrast to functional traits, we found little inter-annual or inter-site variation in simple morphometric traits.