Life Sciences Commons^™

Comparative Reproductive Success Of Yellow-Shafted, Red-Shafted, And Hybrid Flickers Across A Hybrid Zone, William S. Moore, Walter D. Koenig

Biological Sciences Faculty Research Publications

Alternative hypotheses of hybrid zones make specific predictions about reproductive components of fitness in the hybrids. The dynamic-equilibrium and reinforcement hypotheses are premised on reduced hybrid fitness, which should be apparent as reduced clutch or brood size or as increased embryonic mortality. The hybrid-superiority and introgression hypotheses predict normal clutch and brood size and embryonic mortality.

Reproductive success was measured at four study sites on a transect across the hybrid zone between the Yellow- (Colaptes auratus auratus) and Red-shafted (C. a. cafer) subspecies of the Northern Flicker. Two additional clutch size samples representing pure Yellow- and …