We compared physical and vegetative habitat characteristics at 14 dam sites occupied by beaver (Castor Canadensis) with those at 41 random unoccupied reaches to identify features important to dam-site selection in the Long Creek basin, Grant County, Oregon. Stream reaches with dams were shallower and had a lower gradient than unoccupied reaches. Beaver did not build dams at sites with a rock substrate. Bank slopes at occupied reaches were not as steep as those at unoccupied reaches; and occupied stream reaches had greater tree canopy cover, especially of thinleaf alder (Alnus tenuifolia), than did unused reaches. A discriminant model using transformations of bank slope, stream gradient, and hardwood cover classified all beaver dam sites correctly and 35 of 41 random sites as unoccupied sites. The 6 misclassified sites had rock substrates.
We also tested four habitat suitability models for beaver in this basin. Three models produced significantly different (P < .05) scores between occupied and random unoccupied reaches, suggesting that they might have some utility for this region.
McComb, William C.; Sedell, James R.; and Buchholz, Todd D.
"Dam-site selection by beavers in an eastern Oregon basin,"
Great Basin Naturalist: Vol. 50
, Article 9.
Available at: http://scholarsarchive.byu.edu/gbn/vol50/iss3/9