Reducing Human Impacts on White-Tailed Deer and Spotted Salamanders in North America

Reducing human harm to wildlife requires more than installing a crossing structure or recording fewer carcasses. This targeted critical review examines road traffic, habitat fragmentation, forest clearing, and deicing runoff affecting white-tailed deer ( Odocoileus virginianus ) and spotted salamanders ( Ambystoma maculatum ) in North America. Ten primary sources were assessed using their full texts, with attention to sampling units, outcome definitions, study design, and transferability. Evidence supports fencing connected to usable deer underpasses at studied sites, while salamander protection requires attention to migration routes, terrestrial habitat, breeding-water quality, and life stage. However, movement observations, collision counts, experimental survival, and modeled population outcomes measure different processes and cannot be ranked as interchangeable percentages. The review contributes an integrated assessment framework that links exposure reduction, completed movement, habitat suitability, and demographic response. A reconstruction of published salamander counts demonstrates how excluding animals that bypass fences can overstate system performance. The resulting recommendations distinguish supported interventions from plausible measures requiring field validation. Evidence is concentrated in the United States and one Canadian setting; it does not establish a continent-wide effect size or a measured New Jersey outcome. Future evaluations should test whether combined interventions improve both safe movement and subsequent recruitment.