Since 1998, RMBO has been investigating the effects of ponderosa pine restoration activities on breeding bird populations in the San Juan National Forest. This project is part of a larger effort to demonstrate methods for returning ponderosa pine forests to a pre-Columbian state. Participants in the Ponderosa Pine Forest Partnership include Montezuma County, U.S. Forest Service, Colorado Division of Wildlife, Colorado State University, and the Colorado Timber Industry Association. This collaborative effort aims to develop a sound restoration prescription via adaptive management—attempting new management methods, analyzing the outcome, and modifying subsequent efforts so as to develop a restoration prescription that accomplishes the goals of the Partnership.

More than 100 years of fire suppression, grazing, and timber harvesting in ponderosa pine forests have produced a forest structure that differs greatly from pre-Columbian forests. Historically, frequent low-intensity fires maintained an open forest of large trees with a vigorous understory of grasses and herbaceous plants. Compared to pre-Columbian ponderosa forests, modern forests in the Southwest have more trees, smaller trees, fewer large snags, more continuous (less patchy) tree distribution, more oak scrub, and less forb and grass cover. A forest in this condition supports a bird community unlike that of the more open pre-Columbian forest. Restoring modern ponderosa forest to pre-Columbian conditions requires a management prescription of thinning to remove excessive stems, retaining the largest trees, retaining trees in clusters, and implementing periodic prescribed burns to rejuvenate the understory and to regulate the density of young woody plants.

We are working in five demonstration areas to determine the response of the avian community to application of the restoration prescription. We used point counts to survey the bird communities in areas that had been thinned and burned and in nearby undisturbed areas, and compared the results. So far, we have found no wholesale changes in the bird community - nearly all species that were present in the undisturbed areas were also present in the thinned and burned areas. Only the abundances changed. In general, birds that prefer more open forests, including aerial foragers like the Western Bluebird and Violet-green Swallow, were more abundant in the treated areas. This study is quite timely, given the growing interest in thinning and burning Western forests after the wildfires of recent years. RMBO is making valuable contributions to the development of a forest management technique that will become more widespread in the years to come.