Meeting Abstract

64.10  Wednesday, Jan. 6  Wing Morphology in Relation to Migration in Zonotrichia Sparrows CLARK, A.D.*; WANG, G; ADDIS, E.A.; RAMENOFSKY, M; WINGFIELD, J.C.; University of Washington ascaphus@u.washington.edu

Within the Emberizine sparrow genus Zonotrichia, there exist migrant and non-migrant populations with varying degrees of reproductive isolation from the opposing migratory strategy. Taking advantage of both the reproductive isolation and migration behavior gradients in Zonotrichia, I compare wing shapes (specifically aspect ratio and wing pointedness, which are aerodynamically advantageous for long distance migration) within populations, subspecies, species, and the genus. The level of relatedness at which no wing morphology differences can be detected despite differing migratory strategy, appears to be within subspecies. In particular, the non-migratory morphological changes that are seen in resident Z. l. nuttalli, relative to migratory conspecifics, are not seen in non-migrant Z. l. pugetensis individuals from a partial-migrant population relative to migrant Z. l. pugetensis. However, differing wing morphologies were detected between the sister subspecies of non-migrant Z. l. nuttalli, and predominantly migrant Z. l. pugetensis. A steep and marked cline in wing aspect ratio was detected across a 200 mile-long “hybrid-zone” between the Z. l. nuttalli and Z. l. pugetensis breeding ranges, with lower aspect ratios in Z. l. nuttalli and higher aspect ratios in Z. l. pugetensis. Surprisingly, a sex-specific difference in wing shape appears to be conserved throughout all Zonotrichia groups studied, with females exhibiting lower aspect ratios than males, a trait that is independent of sex-specific allometry.