Foraging preferences of the threatened coastal California Gnatcatcher ( Polioptila californica ) during the non-breeding season

Abstract

. We studied the foraging behavior of the federally threatened coastal California Gnatcatcher ( Polioptila californica ), an obligate insectivore, during the non-breeding season, a period of reduced survivorship for this non-migratory passerine due to seasonal aridity and the onset of cold winter storms. During the seasonal dry period in fall (October–November), California Gnatcatchers preferentially foraged in fall-blooming shrubs such as coyote brush ( Baccharis pilularis )