Small‐Mammal Microhabitat Associations and Response to Grazing in Oregon

• DOI: 10.2193/2006-405
• Publication Date: 2008-10-29T22:05:19Z
• Authors: AARON N. JOHNSTON; ROBERT G. ANTHONY
• Keywords: Deer mouse; Vole

Abstract: Livestock grazing is common and widespread throughout North America, yet few studies have evaluated its effects on small mammals. We studied mammals in mixed‐conifer forests oak woodlands the Cascade‐Siskiyou National Monument southern Oregon, USA, to 1) evaluate small‐mammal microhabitat associations, 2) identify riparian‐associated species, 3) test hypothesis that does not influence after accounting for associations. live‐trapped at 16 study sites used logistic regression model probability of capture measured habitat characteristics each trap station grazing. Over 2 years, we trapped 1,270 individual representing 18 species. Odds capturing western harvest mice ( Reithrodontomys megalotis ), dusky‐footed woodrats Neotoma fuscipes long‐tailed voles Microtus longicaudus ) were lower P < 0.05) heavily versus lightly grazed sites. deer Peromyscus maniculatus woodlands, but there was less difference odds between intensities conifer forests. Townsend's vole townsendii riparian areas. Western mice, voles, associated with, obligated to, Deer ubiquitous, captures also higher areas compared with uplands. Siskiyou chipmunks Tamias siskiyou piñon truei uplands rather than Trowbridge's shrews Sorex trowbridgii chipmunks, bushy‐tailed cinerea positively coarse woody debris. Land managers should anticipate herbaceous or shrub cover, particularly areas, will decline when cattle remove this cover.