Pocket Gopher Damage on Ponderosa Pine Plantations in Southwestern Oregon

Abstract

Pocket gophers (Thomomys monticola) often make regeneration of ponderosa pine (Pinus pond4rosa ) difficult in Oregon, because, after logging, the gophers increase in substantial numbers. Efforts to reforest with ponderosa pine can be nullified if many pocket gophers are present, and in such localities control efforts must be constant. This study showed seedling survival of 87 percent in areas free of pocket gophers in contrast to 12 percent in areas occupied by pocket gophers. The conditions that create a suitable pocket gopher habitat are unknown, but they are apparently influenced by the species of trees present before logging, various vegetative responses after logging, elevation, and soil characteristics. 346 Journal of Wildlife Management, Vol. 35, No. 2, April 1971 intensively by any other animal and that No. 227 and No. 228 had only two squares in common. Our data indicate that the young assembled each night about S to 10 minutes before the female returned, even on August 26 when, as described above, the female was 20 minutes earlier than on any previous night. The same mechanism was probably triggering the timing of the female and her young. The gathering place did not appear to be rigidly fixed, apparently varying by 30 to 50 feet between nights, but this was difficult to detexmine precisely because of limitations in ie tracking system.