Meeting Abstract

P1.84  Friday, Jan. 4  Phenotype-environment correlations in Cinclodes ovenbirds: Linking morphology to isotopic niche RADER, J.A. *; NEWSOME, S.D. ; CHESSER, R.T.; MARTINEZ DEL RIO, C.; University of Wyoming; University of Wyoming; National Museum of Natural History, Smithsonian Institution; University of Wyoming jrader@uwyo.edu

The species in the genus Cinclodes (Furnariidae), inhabit coastal and riparian zones from sea level to >4000 m, and some species display seasonal elevational migration. They might represent a good example of an adaptive radiation. We characterized the isotopic niches of 13 species of Cinclodes. We found that species occupied distinct hypervolumes of a δ¹³C, δ¹⁵N, δ¹⁸O, δD isospace. The δ¹³C and δ¹⁵N characterized dietary resource use, whereas the δ¹⁸O and δD axes served as a proxy for altitude. A terrestrial/freshwater habit appears to be ancestral and the most prevalent in the genus. This type of resource use was found in 8 species. The use of tidal marine resources appears to have evolved once and to be found in two species: C. nigrofumosus, C. taczanowskii. The occupancy of islands with mixed reliance on coastal habitats fertilized by seabirds and intertidal habitats appears to have evolved only once, in C. antarcticus. Finally, two species (C. patagonicus, C. oustleti) make use of both marine and terrestrial resources. These two species also seem to exhibit altitudinal movements. The marine/terrestrial mixed use habit seems to have evolved twice. Morphological diversification was determined by principal components analysis of multiple linear measurements. The genus Cinclodes seems to have two primary subclades characterized by relatively large body size, and small body size, respectively. However, the island species, C. antarcticus, a member of the small subclade, seems to have evolved unusually large body size. Stable isotopes appear to be a useful tool to characterize the ecological habits of species and their diversification.