Estimation of the value of vegetation disappearance by prairie dogs and cattle on prairie dog towns in mixed-grass prairie. Beutler, Martin ^*,1, Stoltenberg, Matthew ², Johnson, Patricia¹, ¹ South Dakota State University, Rapid City, SD, USA² South Dakota State University, Brookings, SD, USA

ABSTRACT- In the summer of 2002 and 2003, biomass estimates were made periodically on three mixed-grass prairie pastures in south central South Dakota with varying degrees of prairie dog town coverage. Estimates of forage removed were made for cattle alone, prairie dogs alone, cattle and prairie dogs together, and cattle on off-prairie dog town sites. Forage removed by prairie dogs on on-town sites was found to be nearly three times that of cattle. Cattle removed two times more forage on off-town sites as on on-town sites. Total forage removed on on-town sites (prairie dogs + cattle) was almost two times greater than on off-town sites. The objective of this study was to estimate the value of vegetation disappearance by prairie dogs and cattle found in that previous work. Given an average value of $21.35/AUM for the study period, the total value of vegetation disappearance on on-town sites was estimated to be $13.55/ac. Prairie dogs share of the disappearance was $10.40/ac and cattle, $3.15/ac. The value of forage disappearance by cattle grazing off-town sites was estimated at $7.12/ac. Given that a ranch of 6050 acres would be able to sustain a heard of 200 cattle with 10 months of grazing per year (0.33 AUM's/ac), prairie dog towns covering 5% of the ranch would require the manager to lease 54 AUM's of cattle grazing on neighboring land at an estimated value of $1,163 or $5.82/hd; 15% coverage would require 163 AUM's of leased forage for $3,488 or $17.47/hd additional cost.

KEY WORDS: cattle, prairie dogs, AUM value, economics