Does drought intensify the effects of black-tailed prairie dogs on livestock production and net revenue in semiarid rangelands?

Authors: Augustine, David; RITTEN, JOHN - Colorado State University; Hoover, David; Derner, Justin

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: On ranches in the western Great Plains, black-tailed prairie dogs are well known to have substantial effects on grassland vegetation. However, the degree to which this affects livestock production is uncertain, because weather patterns also have such large effects on grassland productivity. In addition, prairie dog populations often vary in response to disease outbreaks. Livestock producers are often most concerned about the effect of drought on their forage supplies and livestock. During droughts, prairie dogs may create additional hardship by further reducing forage supplies, but research has not measured how severe the impact of prairie dogs might be during droughts. We studied the effects of black-tailed prairie dogs on the productivity and economic returns of yearling steers grazing angeland of eastern Colorado during a series of years that included above-average rainfall as well as severe drought. We found that in pastures occupied by black-tailed prairie dog colonies, livestock weight gain on high productivity soils was reduced in the two drought years (-23% in 2020; -38% in 2022), but not in a wet or average rainfall year, compared to pastures lacking prairie dogs. Cattle from two pastures with prairie dogs were destocked earlier in the drought of 2022 (due to more severe forage shortages) than cattle from remaining pastures, which negatively affected net economic returns more than it did weight gain, resulting in a significant negative effect of prairie dogs on net revenue (-27%) across all soil types during severe drought. Net economic returns were more similar across soil types in wet years, but were reduced by 41% and 25% on low compared to high productivity soils in the two drought years. Where rangeland managers seek to maintain prairie dogs on their lands for conservation reasons, but also want to minimize the effect on livestock production, we suggest focusing prairie dog conservation on low-productivity soil types.

Technical Abstract: In the western Great Plains, black-tailed prairie dogs are well known to have substantial effects on the quantity and nutritional quality of grassland vegetation. However, the degree to which this affects livestock production has been challenging to quantify due to high temporal variability in precipitation and forage growth rates, as well as substantial variation in prairie dog populations induced by periodic disease outbreaks. Here, we examine the effects of black-tailed prairie dogs on the productivity and economic returns of yearling steers grazing semi-arid rangeland of eastern Colorado during a series of years that included above-average precipitation as well as severe drought. We evaluated the degree to which drought suppresses livestock weight gains in the presence versus absence of prairie dogs, and how this effect varied by soil type (low vs. high productivity). Black-tailed prairie dogs significantly reduced livestock weight gain (kg steer-1 cm precipitation-1) on high productivity soils in the two drought years (-23% in 2020; -38% in 2022), but not in a wet or average precipitation year. Cattle from two pastures with prairie dogs were destocked earlier in the drought of 2022 (due to more severe forage shortages) than cattle from remaining pastures, which negatively affected net economic returns more than it did weight gain, resulting in a significant negative effect of prairie dogs on net revenue (-27%) across all soil types during severe drought. Net economic returns were more similar across soil types in wet years, but were reduced by 41% and 25% on low compared to high productivity soils in the two drought years. Coexistence of prairie dogs with livestock production may increasingly depend on spatially explicit management that seeks to minimize control costs and focus prairie dog conservation on soil types where impacts to livestock production are also minimized.