Adverse impacts to wildlife include removal, degradation, or fragmentation of wildlife habitats. Beneficial impacts include actions that conserve or improve habitats, such as big game crucial winter range or nest sites.

Direct impacts to wildlife would result from loss of habitats or from immediate loss of life. Wildlife can be directly disturbed by human activities (e.g., motorized vehicle use, recreation), potentially causing wildlife to abandon a nest site or home range. Disturbance during sensitive periods (i.e., winter, nesting) may adversely impact wildlife populations. The impact from disturbances may be short-term, where the population may be displaced or shift its activities, or long-term, where the population may permanently abandon its home range, threatening its viability. Habitat loss and fragmentation can result from vegetation treatments, fire and fuels management, mineral exploration and development, construction and maintenance of roads and trails, and development of wind-energy facilities.

Indirect impacts to wildlife result from changing habitat characteristics or habitat quality that affect wildlife. Surface-disturbing activities and other actions that remove vegetation and disturb soil can alter habitat quality. Indirect impacts to wildlife also result from actions that alter habitats to make them unsuitable for future habitation by wildlife species.