Meeting Abstract

P1.71  Wednesday, Jan. 4  Of Isotopes and Ovenbirds: Seeking phenotype-environment correlations in South American Cinclodes ovenbirds RADER, J.A.*; NEWSOME, S.D.; MARTINEZ DEL RIO, C.; Univ. of Wyoming, Laramie; Univ. of Wyoming, Laramie; Univ. of Wyoming, Laramie jrader@uwyo.edu

Adaptive radiation is a fundamental concept in ecology, and a primary source of biodiversity. Identifying and describing new examples of adaptive radiation allows us to expand our view of how the process occurs, and to predict its outcomes. Cinclodes, a genus of South American songbirds, is a recent and rapidly diverging taxon that has diversified along several ecological axes. This group of 15 species provides an ideal system in which to study ecological and morphological covariation. Cinclodes species inhabit lowland coastal and riparian zones, as well as very high elevation (>4000 m) riparian habitats, with some species displaying seasonal elevational migration. Other species have adapted to utilize marine resources either seasonally or permanently, and to cope with the concomitant salt loads. These marine Cinclodes may be the most marine adapted of all passerines. Preliminary morphological data suggest that Cinclodes can be divided into two functional groups, or morphotypes, based on bill dimensions: a long, stout-billed morph and a short, gracile-billed morph. The data also suggest morphological convergence among the species C. fuscus, C. albiventris and C. albidiventris. Until a recent molecular study identified that these species are not monophyletic, they were considered subspecies of C. fuscus. Our study also uses carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes as indicators of reliance on marine and terrestrial resources, and deuterium (δD) and oxygen (δ¹⁸O) isotopes to assess patterns of elevational residence and movement. Our study takes a novel approach in the use of morphological and stable isotope covariates to address the challenge of characterizing phenotype and environment, and highlights the value of established museum collections for studies of this variety.