Emerald ash borer (Agrilus planipennis) induced tree mortality alters forest bird communities

Emerald ash borer (Agrilus planipennis, EAB), an invasive wood-boring beetle, has killed millions of ash trees since its accidental introduction from Asia. Ash can be common in the fragmented forests of Midwestern states, and comprises 10% of trees in Ohio’s forests.  The rapid generation of canopy gaps, dead standing trees, and regeneration in subsequent forest strata that result from EAB-induced ash mortality may create new niches for some organisms and narrow or close existing ones, resulting in a cascade of direct and indirect ecological effects on the structure and function of forest communities. We are documenting the effects of ash mortality on communities of breeding birds in 32 fragmented forest sites, representing a gradient of EAB-induced ash decline, across western Ohio. Specifically, our aim is to determine if high densities of EAB adults emerging from and ovipositing on infested trees provides a resource pulse in late spring and early summer that can be exploited by bark foraging birds. Utilizing point transect observations, we showed that as EAB-induced ash decline progressed, bark-foraging birds increased the proportion of time spent foraging on severely declining ash trees relative to other tree genera. Additionally, we quantifed the relationship between EAB-induced ash mortality and alterations to bird community composition linked to fluctuations in habatat availability.