An ecological study of the pocket gopher (Thomomys talpoides tenellus goldman) in the Jackson Hole Region of Wyoming

Authors(s): W. A. Laycock

Publication:

Publisher:

Publication Date: 0000-00-00

Type: MS

Location: Laramie Wyoming

Abstract: The pocket gopher (Thomomys talpoides tenellus) was studied in Jackson Hole and in the mountains surrounding Jackson Hole in Teton county of Wyoming during a three month period in the summer of 1952. The base of operations for the study was the Research Station of the Jackson Hole Wildlife Park. The purpose of the study was to determine the inter-relationship between the pocket gopher and the condition of soil and vegetation on high mountain range lands, and to find out the truth of some of the conflicting viewpoints that exist concerning the pocket gopher. The activities of the pocket gopher were observed in as many localities and situations in the area as possible. The summer and winter ranges of the Jackson Hole elk herd were examined and exclosures were studied to determine abundance of gopher activity inside and out. Other studies designed to learn as much as possible about the activity of the gopher included (1) occurrence of activity in different vegetational types, (2) quadrants for mound count designed to estimate the amount of soil brought to the surface by gophers in a given area, (3) slope measurements to determine maximum slope where activity occurs, and (4) mound revegetation studies. The pocket gopher occurs in varying abundance in most of the plant communities in the Wildlife Park. The highest populations were found in open portions of aspen communities due to favorable moisture, soil, and food conditions. There is one late summer period of apparent gopher inactivity in all areas studied and in the higher elevations there is another period in late spring when no new mounds are formed. The gophers are not dormant during these periods but carry on activity deeper and fill the upper tunnels with the soil excavated instead of bringing it to the surface. The maximum slope where activity was found was a 75 percent or 37? slope. The size of mounds formed in the summer is directly correlated with edaphic conditions. Gophers make larger mounds in areas of deeper, more moist, and less rocky soil. The mound formation and digging activities of the gopher are not the primary or starting causes of erosion in this area but contribute to erosion once it has been started by other causes. The activity of other wildlife have definite influences on the pocket gophers? population and activities. The winter feeding of hay and the maintaining of an overpopulation of elk leads to a very high winter concentration of elk on the winter range. The trampling due to this overconcentration of elk results in a different pattern of mound formation on the winter range than is found anywhere else in the area. While there are numerous summer mounds very few winter cores can be found. The maintenance of this overpopulation of elk has resulted in the overgrazing of portions of the elk summer range. These overgrazed portions have a higher gopher population than areas not yet overgrazed. The increase of plats preferred by gophers as food due to the overgrazing is the probable reason for this increase in gopher population. There was little or no difference in the gopher populations inside the exclosures studied as compared to areas outside these exclosures. Revegetation starts on only a small percentage of gopher mounds the season they are made. There are two types of plants in this revegetation, those surviving covering by dirt and growing through the mound and those which start from seed in the mound. Both types of plants are important in the start of revegetation and eventual plant coverage of the mound.

Keywords: ecology, animal, mammal, gopher, pocket gopher, Thomomys talpoides tenellus, Jackson Hole, Teton County, Teton Mountain Range, Gros Ventre Mountain Range, Jackson Hole Wildlife Park, habitat, elk, wapiti, Cervus elaphus, Cervidae, population, winter food supplementation, feeding, management, National Elk Refuge, food, forage