Songbird use of high-elevation habitat during the fall post-breeding and migratory periods

In light of declining populations of many North American songbirds, there is a need to understand the value of habitats used by species throughout the annual cycle, including the post-breeding and migratory periods. Here, we identified the songbird community and examined habitat use and degree of habitat specialization of species using high-elevation habitats in southern British Columbia in fall. Surveys were conducted along transects in habitats that included alpine grassland, subalpine shrub meadows, and montane coniferous forest. We detected a total of 6,608 individuals representing 70 species. Twelve species dominated the community and represented more than 85% of the observations. Homed lark (Eremophila alpestris) and American pipit (Anthus rubescens) were most abundant in alpine grasslands; yellow-rumped warbler (Dendroica coronata), dark-eyed junco (Junco hyemalis), and white-crowned sparrow (Zonotrichia leucophrys) were most common in semi-open subalpine habitats; and golden-crowned kinglet (Regulus satrapa) and mountain chickadee (Poecile gambeli) were most abundant in continuous coniferous forest. Nearly all species commonly observed in this study also breed at high elevations, while species that breed only at lower elevations were rarely or never observed. This suggests that high elevations are preferred in fall by species that use habitats with similar structure at other times of the year. Species showed considerable variation in habitat specialization. Some, such as homed lark and Lincoln's sparrow (Melospiza lincolnii) primarily used a single high-elevation habitat type, while others such as chipping sparrow (Spizella passerina) and yellow-rumped warbler were common in multiple high-elevation habitats.