The Effects of Elk on Nest Site Selection in Cavity-Nesting Birds in Rocky Mountain National Park

Duberstein, Jennifer

This study found that cavity nesters choose live trees more often than dead trees. Quaking aspen is the most widely-distributed tree in North America. In many areas in Colorado and the West, elk browse in aspen stands on twigs and new suckers and feed on the bark, damaging the tree and discouraging regeneration. The management of the elk population in Rocky Mountain National Park has long been the subject of study and controversy. The author studied cavity-nesting birds in aspen groves on the elk winter range in the park to determine if primary-cavity nesting birds preferentially select for trees of a specific health and whether elk are affecting the availability of potential nest sites. It found that cavity nesters choose live trees more often than dead trees. The consistent deterioration of the overall health of aspen groves in this area of the park could ultimately lead to the extirpation of species of cavity-nesting birds from this area. Understanding the short- and long-term effects of elk on aspen habitat and cavity nesters is vital to the creation and implementation of a successful elk management plan.