COMPETITION AND FACILITATION BETWEEN PRAIRIE DOGS AND LIVESTOCK

Abstract

All photographs by David Augustine. Black-tailed prairie dog on a colony in the Conata Basin of Buffalo Gap National Grassland, South Dakota, USA. Cattle grazing on a black-tailed prairie dog colony at the Buffalo Gap National Grassland, which is adjacent to the Badlands National Park visible in the background. Cattle grazing on a black-tailed prairie dog colony at the Pawnee National Grassland, Colorado. In the Great Plains of North America, black-tailed prairie dogs are often thought to compete with cattle for forage. We examined how prairie dogs affect the amount and quality of forage growing on their colonies in Colorado and South Dakota. At a site experiencing below-average rainfall, forage both on and off colonies was so short and sparse that cattle were likely to be limited by the rate at which they could consume forage, rather than the rate at which they could digest it. In contrast, at sites experiencing above-average rainfall, forage both on and off colonies was tall and dense enough for cattle to be limited by digestion rather than the rate of forage consumption. Overall, our findings show prairie dogs can both enhance and suppress the weight gains of cattle depending on local weather conditions and the proportion of a pasture that is occupied by prairie dogs. Cattle grazing off of a black-tailed prairie dog colony at the Buffalo Gap National Grassland, South Dakota, with Badlands National Park as the backdrop. These photographs illustrate the article “Competition and facilitation between a native and a domestic herbivore: trade-offs between forage quantity and quality,” by David J. Augustine and Tim L. Springer, scheduled for publication in Ecological Applications 23(4), June 2013.