Prairie dog effects on harvester ant species diversity and density

The purpose of this study was to determine if black-tailed prairie dogs (Cy nomys ludovicianus Ord) influence harvester ant nest density and species co mposition within the shortgrass prairie biome of southwestern Kansas. Two t reatments were established: areas colonized by prairie dogs and areas not c olonized by prairie dogs. We recorded 183 harvester ant nests of 3 species, Harvester ant nest density did not differ significantly between prairie do g colonies (3.08 nests ha(-1)) and non-colonized shortgrass prairie sites ( 4.54 nests ha(-1)), but species composition did. Pogonornyumex rugosus Emer y was the most frequent species on prairie dog colonies where it accounted for 87 % of ant nests present, as opposed to 33 % on sites where prairie do gs were absent. Pogonomyrmex barbatus Smith was the most abundant species o n non-colonized areas, making up 49 % of the ant nests sampled. Pogonomyrme x occidentalis Cresson comprised 11 % of ant nests sampled, and was nearly absent from prairie dog colonies (20 nests on non-colonized sites vs. 1 nes t on prairie dog colonies). The average number of harvester ant species fou nd per site was consistently greater on sites where prairie dogs were absen t.