Predation on Artificial Nests in Hurricane-Created Gaps and Adjacent Forest of the Southern Appalachians
Predation rates were compared during three 7-day trials on 742 artificial ground nests located in 10 hurricane-created canopy gaps and IO adjacent closed-canopy controls in the southern Appalachian mountains of North Carolina. White northern bobwhite (Colinus virginianus) eggs were used in trials 1 and 2, but brown-speckled Japanese Quail (Coturnix coturnix) eggs were used in trial 3 to determine: (1) whether artificial ground nests were at a greater risk of predation in gaps than in adjacent closed-canopy forest; (2) whether predation rates increased with successive trials and; (3) whether egg color affected predation rates. Horizontal shrub cover and vertical shrub density up to 1.5 m were greater in gaps than in controls. Seventy percent of artificial nests were depredated, but predation rates ranged from 0-100% among sites and trials in both gaps and controls. Predation rates did not differ between gaps and controls. However, predation rate increased from trial 1 to trials 2 and 3. Egg color did not influence predation rates of artificial nests. Vertical shrub density deterred nest predation in gaps (but not controls), in trials 1 and 2, but had little effect by trial 3. Forest fragmentation by canopy gaps did not adversely affect nesting success of ground-nesting birds, as measured by predation rates of artificial ground nests.