Effect of partial cutting on predation risk to artificial bird nests

Based on relative abundance data, partial cutting has been suggested as a t echnique to maintain habitat for birds associated with late-seral forests, but there has been little study of partial cutting effects on nesting succe ss. One of the primary limitations to nesting success is nest predation. We compared predation rates (proportion of nests disturbed in a 14-day period ) in partially cut (30 or 60% basal area removal), clearcut, and uncut fore sts in northwestern British Columbia, in two experiments using ground-place d (1993) and shrub-placed (1998) artificial nests. In the ground-nest exper iment there was a very low predation rate (0.06) and no detectable differen ce among treatments (p = 0.403). In the shrub-nest experiment, there was a 0.36 predation rate and little evidence of treatment differences (p = 0.295 ). Based on 90% confidence intervals for differences in observed predation rate, the 30% removal clearly did not increase predation risk relative to u ncut forest. With the 60% removal, however, we cannot rule out a possible i ncrease in predation risk compared with either uncut forest or clearcuts.