AbstractsBiology & Animal Science

During the spring of 1963 and 1964 an investigation of a small mammal community was made in McDonald Forest, near Corvallis, Oregon. The revised North American Census of Small Mammals procedure was used, and from this census the species composition of the community was determined. The relationships of several genera indicated a social dominance within the community. The population density remained rather constant over the two year period, but the composition of this population varied a great deal. Peromyscus and Sorex demonstrated a rather large increase from 1963 to 1964, while Microtus and Eutamias numbers dropped. The efficiency of this method was tested by trapping for four additional days in the center of the circle after the regular trapping period. This additional trapping demonstrated that the animals with larger home ranges were completely removed, while animals with small home ranges were still in the area.