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Janet Binns July 15, 2015 Page 6 Shrub and 84 percent in the Pinyon -Juniper vegetation types. Mule deer diets consisted of approximately 89 percent shrubs in the Mountain Shrub and 95 percent in the Pinyon -Juniper vegetation types. Gambel Oak was a dominant shrub in the Mountain Shrub vegetation types, but was not present in the cattle diets. This study confirms the long accepted understanding in the field of range management that cattle are grazers and eat primarily grass, while mule deer are primarily browsers and eat primarily shrubs. Working at the Central Plains Experimental Range on the short grass prairie in northeastern Colorado, studying the grazing habits of cattle, Wallace and others (1977) obtained similar results. In June cattle consumed diets consisting of approximately 86% grass and 14% fortis. In July their diets consisting of approximately 90% grass and 10% forbs. In September their diets consisting of approximately 96% grass and 4% forbs. In December their diets consisting of approximately 99% grass and 1% forbs. Working on the same site, Vavra and others (1977) reported similar findings. In June cattle consumed a diet consisting of approximately 73.33 % grass, 20.00 % forbs and 6.67 percent shrubs. In July their diets consisting of approximately 59.68 % grass, 33.24 % forbs and 7.08 % shrubs. In August their diets consisting of approximately 63.66 % grass, 24.83 % forbs and 11.51 % shrubs. In July their diets consisting of approximately 59.68 % grass, 33.24 % forbs and 7.08 % shrubs. On lightly grazed pastures their diets consisted of approximately 63.43 % grass, 32.68 % forbs and 3.89 % shrubs. On heavily grazed pastures their diets consisting of approximately 66.50 % grass, 22.40 % forbs and 11.10 % shrubs. Working on the southern portion of the Great Plains at the Fort Stanton Experimental Ranch in southcentral New Mexico on open grassland dominated largely by Blue Grama, interspersed with Pinyon -Juniper on the slopes and at higher elevations, Pfister and others (1984) reported that cattle diets over the two-year study consisted of approximately 60 percent grasses, 30 percent forbs and 10 percent shrubs, consisting of Fourwing Saltbush and Wavyleaf Oak. Their data were all presented in graphs so more refined estimates are not available. These four representative grazing studies confirm that cattle and Mule deer do not consume forage proportional to its abundance in the field, but rather in direct response to their preference for those foods. Changing Regulatory Definition of "Woody Plants." One important point which needs to be pointed out is that the CDRMS (old CMLRB) has changed the definition of shrubs since the original woody plant density requirement for the Southfield Mine was originally developed in about 1980. In the original federal OSM and state CMLRB regulations issued in 1977 and 1978 respectively, all woody plants were initially included in the calculation of the woody plant density revegetation success standard. Subsequent to this initial rule making, the OSM revised their definition of woody plants and dropped half -shrubs or suffrutescent plants from their definition of woody plants and the CMLRB did the same by changing Rule 4.15.8 to read that the woody plant density includes the "number of countable tree and shrub stems per unit area."