Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 12, 2011
Publication Date: December 30, 2012
Citation: Augustine, D.J., Springer, T.L. 2012. Competition between cattle and black-tailed prairie dogs in the western Great Plains: Assessing tradeoffs between forage quality and quantity. Society for Range Management Meeting Abstracts No. 0187. Technical Abstract: Black-tailed prairie dog (BTPD) and cattle diets overlap substantially, but few studies have quantified the degree to which negative prairie dog effects on forage quantity on may be offset by increased forage quality. During 2009 - 2010, we measured spatial and temporal variability in forage quantity (biomass) and quality (in vitro dry matter digestibility and protein content) on versus off BTPD colonies at a site in northern mixed prairie (South Dakota) and two sites in shortgrass steppe (Colorado). In northern mixed prairie, prairie dogs significantly reduced forage quantity by 63%, and increased in vitro digestibility by 16%. At one shortgrass colony complex, BTPD reduced forage quantity by 37%, but had no effect on digestibility. At the second shortgrass complex, BTPD increased forage digestibility slightly (by 5.2%) but had no effect on forage quantity, likely due to above-average precipitation. Measurements in 2010 revealed increasingly negative BTPD effects on forage quantity over the course of the growing season at all 3 complexes (30%, 36% and 48% reduction in May, July and September respectively). At the same time, BTPD enhancement of forage digestibility increased over the growing season, from 6.8% in May to 8.6% in July and 9.0% in September. Findings demonstrate substantial spatiotemporal variability in prairie dog effects on forage quality and quantity across the Great Plains, related to variation in grass species and weather. Data provide a basis to assess prairie dog – cattle competition relative to the proportion of a pasture occupied by colonies and cattle foraging patterns.