Edge-related nest predation in clearcut and groupcut stands

Edge-related increases in nest predation rates have been reported in forest adjacent to clearcuts. Group selection is an uneven-age silvicultural technique that may provide an alternative to clearcutting, but group selection creates more edge per unit area cut than does clear cutting. Thus, if edge-related increases in nest predation exist in forest adjacent to groupcuts, group selection may potentially result in higher rates of edge-related nest predation than does clearcutting. To test this, we deployed 80 artificial shrub nests baited with Zebra Finch (Poephila guttata) eggs in edge areas (0-5 mfi om edges) and interior areas (45-50 m from edges) adjacent to clearcuts and groupcuts. The probability of a nest being depredated was higher in edge ar eas than interior areas (p = 0.02) and was independent of nest concealment nest height, or whether the nest was adjacent to a clearcut or a groupcut (p = 0.18). Thus, we conclude that forest edges created by groupcut Sing are associated with increased levels bf nest predation in adjacent forest, that the magnitude of this edge effect is similar to increases in nest predation in forest adjacent to clearcuts, and therefore that the abandonment of clearcutting in favor of group selection cannot be justified on the basis of concerns about the welfare of mature forest-dwelling birds.