Mixed Species flock composition associated with Chesnut-Backed Chickadees

From 2000 to 2001 we investigated mixed species flocks associated with the Chestnut-backed Chickadee (Poecile rufescens) during fall migration. Out of 32 species, three PIF riparian focal species, Warbling Vireo, Wilson's Warbler, and Yellow Warbler (Dendroica petechia), were among the four most frequent species observed flocking with the Chestnut-backed Chickadees. Preliminary results suggest that the Chestnut-backed Chickadee plays an important role as a nuclear species in the flocking behavior during migration stopover for these three riparian focal species.