Increased avian insectivory in a fragmented temperated forest

Abstract

Habitat fragmentation increases the temporal variability in species richness and abundance of forest birds. Therefore, changes in the ecological interactions at which birds are engaged might be transient. Furthermore, despite changes in insectivory rates might have cascading effects if such changes are permanent, there are no evaluations of the persistency of changes in insectivory rates. In this study, we assessed the persistency of changes in insectivory in forest fragments, comparing the intensity of insectivory upon artificial insect larvae at three different years at a single site in central Chile. In coastal Maulino forest, the intensity of insectivory is persistently higher in forest fragments compared to continuous forest. An increase in insectivory might reduce herbivorous insect abundance which is translated into higher growth rates in seedlings at forest fragments, a factor that is changing forest dynamics. Our study suggests that the variation in bird insectivory on fragmented forest is a permanent phenomenon, which might have profound implication for the dynamics of the forest remnants.