Black-Tailed Prairie Dogs, Cattle, and the Conservation of North America’s Arid Grasslands

<div><p>Prairie dogs (<i>Cynomys</i> spp.) have been eliminated from over 95% of their historic range in large part from direct eradication campaigns to reduce their purported competition with cattle for forage. Despite the longstanding importance of this issue to grassland management and conservation, the ecological interactions between cattle and prairie dogs have not been well examined. We address this issue through two complementary experiments to determine if cattle and prairie dogs form a mutualistic grazing association similar to that between prairie dogs and American bison. Our experimental results show that cattle preferentially graze along prairie dog colony edges and use their colony centers for resting, resembling the mutualistic relationship prairie dogs have with American bison. Our results also show that prairie dog colonies are not only an important component of the grassland mosaic for maintaining biodiversity, but also provide benefits to cattle, thereby challenging the long-standing view of prairie dogs as an undesirable pest species in grasslands.</p></div

Small-scale experiment.

<p>Cattle grazing record’s percentage by foraging zone and season v.s. foraging zone area cover %. (a) Bonferroni confidence-interval results (P <0.001) are given by the following signs: “<b>+</b>” indicates preference (utilization above availability); “<b>=</b>” indicates random (utilization equal to its availability); and “–” indicates avoidance (utilization below its availability); (b) image of a typical prairie dog colony in the Janos grasslands, showing vegetation height and cover increasing away from the colony center (1) towards the colony edge (2) and the surrounding climax grasslands (3).</p

Large-scale experiment.

<p>Cattle record’s percentage by vegetation type, activity, and season. a) Total time cattle utilized the different vegetation types v.s. vegetation type % cover; b) Grazzing records by vegetation by season v.s. vegetation type cover %; c) Grazzing records by vegetation x season v.s. vegetation type cover %. d) Grazzing records by vegetation x season v.s. vegetation type cover %. Bonferroni confidence-interval results (P <0.001) are given by the following signs: “<b>+</b>” indicates preference (utilization above availability); “<b>=</b>” indicates random (utilization equal to its availability); and “–” indicates avoidance (utilization below its availability); and “<b>*</b>” indicates vegetation types with significant differences in utilization across seasons.</p

Spatial pattern of the three classes of cattle activity relative to the vegetation/ground cover types through seasons.

<p>Colored dots indicate cattle locations by activity across all weeks during each sample season.</p