Effects of clearcutting a Douglas-fir stand upon small animal populations in western Oregon

An ecological study of small forest mammals was conducted from 1964 to 1970. The objectives were to obtain chronological information relative to the effects of current logging practices on vegetational succession and small mammal populations. The locale of the study was in the west-central Cascade Mountains of Oregon. The principal timber species was Douglas-fir, Pseudotsuga menziesii. The climate was characterized by heavy precipitation in the winter and dry summers. Snowfall varied from slight to heavy. Elevation was 3000 feet. The study areas were composed of a 125-year-old timbered control unit, a clearcut non-burned unit, and a clearcut slash-burned unit. Density and distribution of the small mammals were determined by live-trapping and release of marked animals. Reproductive information of some species was noted. Home range areas was computed for the more numerous species of rodents. More than 4530 individual small mammals of 23 mammalian species were marked on the three areas during the six years of the study. Over 90 percent of the total animals caught consisted of five species: Sorex spp, Eutamias townsendii, Peromyscus maniculatus, and Microtus oregoni. The small mammal densities varied from year to year. They were comparable between units on a monthly basis except for the unburned clearcut unit which differed for a year following logging. Shrew numbers, abundant in the forest, were less on the unburned and sharply reduced on the slash-burned unit. Deermice, scarce in the closed forest, increased greatly in numbers on the clearcuts. Chipmunks were abundant in the forest, less on the slash- burned clearcut unit, and sharply reduced in numbers on the unburned unit. Creeping mice were scarce in the forest but their numbers erupted on the clearcuts. Snowshoe hares were, caught periodically in the timber but not on the clearcuts. Some species, caught infrequently or known only by sign, are expected to increase and become more numerous as the vegetation becomes brushier. These include the snowshoe hare, mountain beaver, porcupine, and the pocket gopher. The results of this study suggest that more information is required relative to the diet of the small mammals. Effects of vegetational manipulation, by selective cutting practices or by the use of herbicides on small mammals should be examined

The porcupine in Oregon : its life history and control

This note was prepared to answer the questions most of ten asked by foresters concerned about the porcupine and its control. The literature was reviewed for information on the animal's life history and the extent of damage in other areas. Direct field work reported was done primarily near Medford, Oregon, in mixed species. Because of the increased amounts of damage occurring west of the Cascade Mountains, however, some observations were made in stands that were almost all Douglas-fir. It should be understood that control measures are under-taken only after the porcupine has become a pest animal and is causing damage to future crop p-ees. Porcupine populations occurring in noncommercial timber-producing areas are con­sidered as desirable components of the wilderness wildlife