Burrow diameters of five small mammal species, Townsend's ground squirrel (Spermophilus townsendii), Wyoming ground squirrel (S. elegans), Ord's kangaroo rat (Dipodomys ordii), montane vole (Microtus montanus), and deer mouse (Peromyscus maniculatus), were examined. Burrow cross sections were noncircular for all species with horizontal diameters 1.2–1.6 times wider than vertical diameters. Montane vole and deer mouse burrows were the smallest diameter, burrows of Wyoming and Townsend's ground squirrels were the largest, and kangaroo rat burrows were intermediate. Soil bulk density and texture significantly affected burrow diameters of montane voles and deer mice but not the other three species.
Laundré, John W.
"Horizontal and vertical diameter of burrows of five small mammal species in southeastern Idaho,"
Great Basin Naturalist: Vol. 49
, Article 24.
Available at: http://scholarsarchive.byu.edu/gbn/vol49/iss4/24