Great Basin Naturalist


Five species of the coccidian genus Eimeria (E. beecheyi [prevalence = 17.9%], E. callospermophili-morainensis[28.6%], E. larimerensis [16.1%], and E. bilamellata [3.6%]) were recovered from 56, 13-lined ground squirrels (Spermophilus tridicemlineatus) collected from two sites in eastern Wyoming. Two squirrels from one site were also passing an unidentified polysporocystic coccidian. Infected squirrels were found to harbor from one to three species simultaneously. Previously these same eimerian species were found infecting sympatric populations of Wyoming ground squirrels. (Spermophilus elegans) and white-tailed prairie dogs (Cynomys leucurus) at one of the sites; it is suggested that the exchange of these generalist parasite species among co-occurring sciurid hosts contributes to the consistent prevalence levels reported in Wyoming ground squirrels.