In the western United States, human activities have decreased black-tailed prairie dog (Cynomys ludovic-ianus) populations to <10% of their historic extent. These animals are ecosystem engineers that radically alter soil physical and chemical characteristics and plant communities on their colonies. We tested the hypothesis that prairie dogs have an impact on higher levels of grassland ecology by measuring the differ-ences in arthropod community structure and burrowing owl foraging on those arthropods, between reintro-duced colonies and adjacent grassland in southern New Mexico, USA. Arthropod communities differed be-tween colonies and grassland in both number of taxa and abundance. Burrowing owls foraged more on col-onies, and caught more prey on colonies compared to grasslands. Pursuit times of burrowing owls in grass-land were longer than pursuits on colonies. Burrowing owls nesting on the edge of colonies foraged extens-ively on colonies, and edge and center-nesting owls delivered similar proportions of prey captured on colonies to their nests. This study suggests that prairie dogs play a vital role in structuring arthropod commun-ities and provide foraging resources for other grassland species.