. The bison of Yellowstone National Park. American bison; Mammals. Habitat Relationships 105. Fig. 48. Bison horning effects on a lod- gepole pine. wallows could still be discerned, although no differences between the vegetation within and around the depressions were apparent. When situated on slopes, wallows sometimes formed focal points of erosion, particularly in the shallow sandy soils of the hills in the south- west part of Hayden Valley. The presence and continued use of such sites did not appear to be re- lated to population levels; some of these places were used before the present stud
. The bison of Yellowstone National Park. American bison; Mammals. Habitat Relationships 105. Fig. 48. Bison horning effects on a lod- gepole pine. wallows could still be discerned, although no differences between the vegetation within and around the depressions were apparent. When situated on slopes, wallows sometimes formed focal points of erosion, particularly in the shallow sandy soils of the hills in the south- west part of Hayden Valley. The presence and continued use of such sites did not appear to be re- lated to population levels; some of these places were used before the present study (Kittams 1949) and show no change in spite of greatly reduced bison numbers. Bulls were commonly seen every year and at all seasons on some of these sites, which suggested that as long as any bison inhabited Hayden Valley these favored places re- ceived heavy use. Revegetation of favored wallows might occur only without a bison population. Trails used by bison, such as the network within Hayden Valley (Fig. 50) and those connecting main use areas such as the Mirror Plateau and Upper Lamar, were also features which appeared only indirectly related to population numbers. These routes were used historically, as now, because of habits and distribution patterns. Areas of thermal activity used by bison, where hot pools and geysers are located, sometimes show breakage of sinter deposits by trampling. Because the rock de- posits form slowly, the effects may be apparent for years. Mixed herd groups used such areas infre- quently and for brief periods, ac- cording to the severity of winter- ing conditions, as discussed pre- viously. Some wintering bulls used certain thermal areas throughout the winter every year regardless of changes in bison numbers. Locations where debarked trees, wallows, trails, and trampling of thermal areas were most noticea-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration an
Size: 1117px × 2237px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorunitedstatesnatio, bookcentury1900, booksubjectmammals
