Attributes / relations provided by
♦ 1Comparative Diets of Burrowing Owls in Oregon and Washington, Gregory A. Green, Richard E. Fitzner, Robert G. Anthony and Lee E. Rogers, Northwest Science, Vol. 67, No. 2, 1993, pp. 88-93
♦ 2Microtus montanus, Wendy E. Sera and Cathleen N. Early, MAMMALIAN SPECIES No. 716, pp. 110 (2003)