Response of an avifauna community to the La Tuna Fire in the Verdugo Mountains of Southern California

Fire regimes in coastal sage scrub and chaparral ecosystems have been found to reshape the distribution of vegetation and lead to changes in avian community composition. Although it is evident that these changes may be reflected in both community diversity and the structure of foraging guilds, the direction of response among habitats remains unclear. Here, patterns of change to an avifauna community were investigated in response to the 2017 La Tuna Fire at one monitoring site in the Verdugo Mountains of Southern California. Avian community diversity and evenness at this site were unaffected, however the structure of foraging guilds was significantly altered. There was a 44.2% increase in counts of insectivorous birds, a 69.6% increase in counts of generalist birds, and a 40.0% decrease in counts of granivorous birds. Principal component analysis suggests that this guild shift is explained by increases in the number of insectivorous and generalist birds present following the fire rather than by decreases in the number granivorous birds. Although post-fire distribution may be related to vegetation structure, interspecific interactions, and species unique adaptations to this habitat, results here suggest that patterns of avifauna community response to wildfire in these ecosystems do not always follow expected patterns and may be dictated by variable causes.