Niche expansion leads to small-scale adaptive divergence along an elevation gradient in a medium-sized passerine bird.

ABSTRACT: Niche expansion can lead to adaptive differentiation and speciation, but there are few examples from contemporary niche expansions about how this process is initiated. We assess the consequences of a niche expansion by Mexican jays (Aphelocoma ultramarina) along an elevation gradient. We predicted that jays at high elevation would have straighter bills adapted to feeding on pine cones, whereas jays at low elevation would have hooked bills adapted to feeding on acorns. We measured morphological and genetic variation of 95 adult jays and found significant differences in hook length between elevations in accordance with predictions, a pattern corroborated by analysis at the regional scale. Genetic results from microsatellite and mtDNA variation support phenotypic differentiation in the presen

SUBMITTER: McCormack JE 

PROVIDER: S-EPMC2603212 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature