Winter presents a special set of problems for wildlife. Most of the disturbance concerns described above take on particular urgency during the winter months. Snow compaction makes digging through snow much more difficult, a serious issue for small mammals that survive in the spaces beneath the snow, and for deer, elk, and other ungulates that must dig through snow to reach critical forage. Snow compaction can be a serious issue for small carnivores, such as pine marten, which rely on the space under the snow for protection from winter conditions, protection from predators, and access to the small mammals which form their prey base. Snowmobile use can also pose a serious threat to species like grizzly bear and wolverine, because, for instance, snowmobile disturbance can lead them to the abandon their dens.
Many wildlife species rely heavily on their ability to hear for survival.
Exposure to ORV noise can adversely affect the ability of wildlife to locate prey, avoid predators, find mates, and perform other critical life functions. Even noise levels that seem reasonable to human ears can be damaging to the critical and highly acute hearing of many wildlife species. As noted above, ORVs can have an enormous impact on vegetation. By reducing the abundance and diversity of many plant species and by changing species composition, the habitat characteristics on which various wildlife species rely can be dramatically degraded. This can result in increased mortality and decreased reproductive success, as wildlife are forced to rely on suboptimal habitat or to exert precious energy in an effort to locate alternate habitat areas.