Edge effects on nest predation in the Shawnee National Forest, southern Illinois

Edge habitats may be considered ‘ecological traps’ for breeding birds if they attract many birds because of apparently favorable nesting conditions but have higher nest predation levels than interior habitats. Four alternative, nonexclusive hypotheses have been suggested to explain why edges might have higher predation levels than interior habitats: (1) predator activity is higher in areas with higher prey density (density-dependent predation);...