Snags and Cavity-Nesting Birds within Intensively Managed Pine Stands in Eastern North Carolina, USA

Abstract

Abstract Although snags are often considered to be a limiting factor for cavity-nesting birds within intensively managed pine (Pinus spp.) stands, there is little information regarding occurrences of snags and cavity-nesting birds for such stands in the southeastern United States. Therefore, during 2002–2003, we measured characteristics of individual snags (n = 1,218) and quantified the relative abundance of cavity-nesting birds (n = 204 observations; nine species) in 35 forest stands representing seven thinning classes (prior to thinning, three age classes following a first commercial thinning, and three age classes following a second commercial thinning entry) in intensively managed pine stands in eastern North Carolina. Snag populations were dynamic, with 649 snags falling and 75 new snags recruited between years. Stands in later thinning classes tended to have snags with larger diameters, less bark, and fewer limbs, and they were taller and more decayed (P < 0.05). Our data suggest that neither density of snags (P = 0.31) nor relative abundance of cavity-nesting birds (P = 0.25) differed strongly among thinning classes. Without active management, low recruitment coupled with the high loss rates that we observed ould lead to low snag densities in older managed stands. Therefore, we suggest that forest managers consider retaining large-diameter dead or live trees as reserve trees through multiple rotations to increase or maintain snags in managed stands.