Small Mammals, Their Parasites and Pathologic Lesions on the Arid Lands Ecology Reserve, Benton County, Washington

Abstract

During May-June 1968 small mammals were sampled on the U. S. Atomic Energy Commission's Arid Lands Ecology Reserve in Benton Co., Washington. A total of 875 trap nights of effort were ex- pended capturing 302 small mammals in seven vegetation associations at seven elevations between 750 and 3500 ft. Species included Perognathus parvus, Peromyscus maniculatus, Lagurus curtatus, Spermophilus town- sendii, Eutamias minimus, Onychomys leucogaster, Thomomys tal- poides and Neotoma cinerea. Perognathus and Peromyscus were caught in most of the vegetation associations sampled, although pocket mice dominated mammalian fauna at lower elevations and deer mice became dominant at higher elevations. Onychomys was trapped only in the ArtemisialPoa association, while the other species, especially L. curtatus, showed a preference for Artemisia/Agropyron. Ten species of fleas and two species of ticks were collected. Meringis shannoni was the most abundant flea and occurred on five hosts. Thrassis bacchi johnsoni, potentially one of the most important flea vectors of sylvatic plague, was collected on L. curtatus. A spectrum of minor pathologic lesions and endoparasitic burdens was documented for Perognathus and Peromyscus.