Laserfiche WebLink
<br />important is through some change in the type and abundance <br />of the food supply upon which they depend and secondly through <br />direct effect on the animal. <br /> <br />Two ecology projects conduc~ed as a part of the Bureau <br />of Reclamation's Project Skywater in the Medicine Bow Mountains <br />of Wyoming and the San Juan Mountains of Colorado have studied <br />mammals. Elk and mule deer were selected ,as index species <br />for intensive study. <br /> <br />The Wyoming study determined ~hat: <br /> <br />"The effects of snow depths on elk cannot be generalized <br />for all winter ranges. Each location of elk winter <br />range has considerable va~iation in topography, <br />vegetation, and climate. I~ is apparent that the <br />animals have more difficulty surviving during cold, <br />heavy snow depth winters. Results from this study <br />would indicate that target areas for increased snow <br />accumulation through weather modification programs <br />should be above the upper ~imits of the elk winter <br />range, about 2,620 meters (8,600 feet) for this <br />study area, and that an additional 15 to 30 percent <br />of snow at high elevations ~ould have no adverse <br />effects on elk. <br /> <br />"With regard to mule deer, sn~w cover does not neces- <br />sarily play an important role in the timing of spring <br />and fall migrations. Deer seem to prefer certain <br />habitats for the purpose of breeding and fawning. <br />Increased snowpack above 2,'743 meters (9,000 feet) <br />would not affect mule deer directly. However, snowpack <br />increase below this elevation could, magnify already <br />eXisting problems by reduCing still further the <br />available winter range." (8) <br /> <br />The San Juan Ecology study provided some additional infor- <br />mation regarding the impacts on elk. It was found that the <br />initiation of winter migration of elk is in response to increasing <br />snow cover, that snow depthS approaching 40 centimeters (16 <br /> <br />2-11 <br />