• Rocky Mountain Research Station
• 240 West Prospect
• Fort Collins, CO 80526
• (970) 498-1100

Understanding the Interaction Between Fire and Woodpeckers as a Means for Guiding Forest Management Practices

Woodpeckers provide multiple beneficial roles in forested ecosystems and are sensitive to forest management practices. They create cavities for a host of SCN species that use them not only for nests but also as roost sites for protection from predation and winter weather. Woodpeckers are also good indicators of forest bird diversity because they are often forest obligates and foraging specialists. Additionally, woodpeckers are sensitive to human alteration of disturbance processes like fire, because these management practices can change the structure and function of forests on which they depend. Thus, woodpeckers, such as the hairy woodpecker (Picoides villosus) in the Southwest, are frequently used as Management Indicator Species (MIS). In northern Arizona, hairy woodpeckers are the most abundant woodpecker species and make one to several new nest and roost holes each year. Because hairy woodpeckers likely provide the majority of cavities for SCNs and mammals in this system, it functions as a keystone species.

Researchers from the Flagstaff Lab initiated a study on the home range and foraging ecology of the hairy woodpecker, the most abundant PCN in northern Arizona likely providing the majority of cavities for SCNs. Relative abundance, diurnal home range size, foraging habitat selection, and insect abundance were measured within high and moderate burn severities at four post-burn ages and in unburned controls. Results indicated that prey resources and vegetative structure resulting from wildfire and subsequent changes as burns age, ultimately drives the selection of habitat by hairy woodpeckers at multiple scales. For example, hairy woodpecker home range size increases as burned areas age. Relative abundance was greatest in high-severity burned areas relative to moderately burned and unburned areas and abundances in all three areas also decreased with post-burn age. Hairy woodpeckers foraging behavior and habitat selection also differed between burn severity and burn age.

These findings will not only help researchers understand the relationship between woodpeckers, fire, and insects but help forest managers implement effective management for this MIS species. Management strategies need to take into account the dynamic relationship on both the spatial and temporal scales. This study suggests that how wildfire is returned to fire-adapted ecosystems is important. Fire frequency, size, severity, severity patch size, and patch distribution all determine the final landscape-level mosaic that wildfire creates. Silvicultural treatments that retained small patches of high density, small diameter stands within a broader matrix of thinned stands might produce the highest quality habitat for hairy woodpeckers because it would create patches of high-severity burn. If salvage logging is undertaken in large high-severity burned areas, dead trees along the perimeter should be retained as they were more heavily used than those in the interiors by hairy woodpeckers for foraging. The resulting mosaic thus determines the presence, abundance and distribution of bark dwelling insects, which can affect the likelihood and structural impact of future fires and the distribution, abundance, and behavior of hairy woodpeckers.

References

http://www.rmrs.nau.edu/publications/Covert-Bratland_Thesis/Covert-Bratland_Thesis.pdf, and

Covert-Bratland, K.A., W. M. Block, and T. Theimer. 2006. Hairy woodpecker winter ecology in ponderosa pine forests representing different ages since wildfire. Journal of Wildlife Management 70: in press.