Response of an Avifaunal Community to the La Tuna Fire in the Verdugo Mountains of Southern California

Abstract

In California’s coastal sage scrub and chaparral, fire reshapes the distribution of vegetation and the composition of bird communities, although the direction of the response in various habitats remains unclear. We investigated changes in the bird community at one site following the 2017 La Tuna Fire in the Verdugo Mountains of southern California. We found that the community’s diversity and evenness did not change, but the structure of foraging guilds did. Counts of omnivores and aerial and generalist foragers increased significantly, whereas counts of granivores and shrub foragers decreased. The number of insectivores decreased slightly, and ground foragers appeared unaffected. Principal components analysis suggests positive, neutral, and negative responses of birds associated with these guilds were driving differences in their abundances after the fire. We show how post-fire bird distributions may be related to fire severity, vegetation structure, and interspecific interactions. However, differences between our results and those of other studies suggest that patterns of bird community response to wildfire may be dictated by factors both related and unrelated to the fire over broader time scales.