Effects of wildfire on densities of secondary cavity-nesting birds in ponderosa pine forests of northern Arizona
|Authors:||Jill K. Dwyer, William M. Block|
|Station:||Rocky Mountain Research Station|
|Source:||In: Moser, W. Keith; Moser, Cynthia E., eds. Fire and forest ecology: innovative silviculture and vegetation management. Tall Timbers Fire Ecology Conference Proceedings, No. 21. Tallahassee, FL: Tall Timbers Research Station: 151-156|
AbstractMany catastrophic wildfires burned throughout forests in Arizona during the spring and summer of 1996 owing to severely dry conditions. One result of these fires was a loss of preexisting tree cavities for reproduction. In ponderosa pine (Pinus ponderosa) forests most cavities are found in dead trees; therefore, snags are a very important habitat component for cavity-nesting species. Thls study focused on the impacts of wildfire on bird populations within 3 ponderosa pine forests throughout northern Arizona. We present preliminary results from the first bird breeding season following the fires.
We randomly established points throughout areas that represented 3 burn severities: severely burned, moderately burned, and unburned. We conducted fixed-radius point counts and nest searches throughout the breeding season. Secondary cavity-nesters as a group did not show significant differences in relative abundance among 3 categories of fire severity. When analyzed at the species level, however, the wildfires did affect the relative abundance of 2 secondary cavity-nesting species, western bluebirds and mountain chickadees. We found no secondary cavity-nests in severely burned areas, most likely due to the lack of cavities after the fire.