Berry, KH. 1980. A review of the effects of off-road vehicles on birds and other vertebrates. Proceedings of the Management of Western Forests and Grasslands for Nongame Birds, compilers RM DeGraaf, and NG Tilgham, 451-67 Ogden, Utah: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station.
RELEVANT TO: ROADS/OFF-ROAD VEHICLES
INVASIVE SPECIES
VEGETATION AND WILDLIFE
MONITORING/ADAPTIVE MANAGEMENT
DESCRIPTION
This 1980 paper reviews five scientific papers that address off-road vehicle (ORV) impacts on birds, and several additional papers on ORV impacts on fishes, amphibians, reptiles and mammals.
MAJOR FINDINGS
- By 1979 the Council on Environmental Quality viewed the ORV problem as one of the most serious public land use problems of the day. Several review papers and bibliographies have covered a number of ORV topics. (p. 451)
- Studies of impacts of ORVs on birds indicate that ORVs can have profound and highly significant negative impacts by reducing abundance, variety, and biomass. (p. 452-4)
- Similar results have been obtained in studies of other vertebrate species, particularly reptiles and small mammals. Numbers, diversity, and biomass are markedly reduced in most species exposed to moderate and intensive ORV use. (p. 455)
- One study reported that ORV noise induced birds to abandon concealing vegetation and fly from 0.8 to 3.2 km away from the sound of approaching vehicles. Wild turkeys also fled at the approach of vehicles. (p. 456)
- Studies have indicated that ORV noise damages hearing abilities of desert kangaroo rats and Mojave fringe-toed lizard, and maladaptive behaviors were induced in Couch's spadefoot toad. (p. 451)
- Many papers on soils and vegetation indicate negative effects on bulk densities and surface strengths; moisture, infiltration rates, porosity and permeability; nutrient values; and runoff. (pp 459-60)
- The paper concludes: "With information existing today, biologists and land-use managers should exhibit stringent precautions and restrictions in selection of areas for ORV use and in managing that use. Data gathered to date indicate that most wildlife species and habitats are highly sensitive to light, moderate, and heavy vehicle use and that major deleterious impacts can occur to ecosystems." (p. 461)
QUESTIONS RAISED FOR THE THREE FORESTS
- How are impacts of ORVs on wildlife populations being incorporated into current planning?
- How are the Forests planning to incorporate long-documented ORV impacts into their planning for sensitive species?
- How are Forests planning to address ORV reduction of moisture, infiltration rates, porosity and permeability in light of predicted drought?
RELEVANCE TO FOREST MANAGEMENT
- Choice of motorized routes on the Three Forests should be based on need, lack of alternatives, and explicit acknowledgement of adverse ecological impacts.
- The Forest Plan EIS must explicitly acknowledge in its analysis of environmental consequences the full range of wildlife impacts known to be posed by ORV use, including light use.
- All sensitive and declining species habitat needs to be subjected to analysis of implications potential ORV degradation.