Avian Nest Survival in Coastal Forested Buffer Strips on Prince of Wales Island, Alaska

• Published in: The Condor
• Main Authors: David M. Sperry, Michelle Kissling, T. Luke George
• Format: Text
• Language: English
• Published: American Ornithological Society 2008
• Subjects: Pacific; Prince of Wales Island; Alaska
• Online Access: https://doi.org/10.1525/cond.2008.8601

In an effort to provide wildlife habitat and link blocks of forested habitat, coastal forested buffer strips in the Pacific Northwest are managed to mitigate effects of fragmentation that result from timber harvesting adjacent to a coastline. We examined the effect of coastal forest buffer strip width on avian nest survival on Prince of Wales Island, Alaska, in 2003 and 2004. We established nest monitoring plots in two buffer width treatments, narrow ( 350 m, n = 3), and monitored a total of 142 nests of six species: the Pacific-slope Flycatcher (Empidonax difficilis), Chestnut-backed Chickadee (Poecile rufescens), Winter Wren (Troglodytes troglodytes), Swainson's Thrush (Catharus ustulatus), Hermit Thrush (Catharus guttatus), and Varied Thrush (Ixoreus naevius). We modeled and compared the daily survival rate (DSR) of each species in both buffer width treatments. Point estimates for DSRs were slightly higher within wide buffers, but confidence intervals overlapped for all species. Overall, Pacific-slope Flycatchers had the highest nest success (87%) and Varied Thrushes had the lowest (22%). In addition, we used an information-theoretic approach to examine support for hypotheses concerning the effects of edge on nest survival of the Hermit Thrush, the only species for which we had sufficient data. Hermit Thrush nest survival was negatively affected by proximity to the coastline. Predators associated with the productive intertidal zone likely increase the predation risk of Hermit Thrush nests located near the coast.