Habitat classification models for beaver (Castor canadensis) in the streams of the central Oregon Coast Range

During 1988-1989, 22 stream habitat attibutes were measured and compared between 40 beaver-dam sites and 72 unoccupied stream sites to identify attributes associated with dam-site selection by beaver (Castor canadensis) in streams of the Drift Creek Basin, Lincoln County, Oregon. Beaver built dams in areas with wide valley-floors; narrow, low gradient streams; high grass/sedge cover; and low red alder (Alnus rubra) and shrub cover. Unoccupied sites lacked these characteristics. A discriminant function model correctly classified 83% of beaver-dam sites and 88% of unoccupied-stream sites with a chance-corrected classification rate of 69% (Cohen's Kappa statistic). We used 3 geomorphic attributes (stream width, gradient, and valley floor width) and developed a new Habitat Suitability Index (HSI) model for the basin. Land managers can use the discriminant function model or the HSI model to inventory potential beaver-dam sites along streams of the Oregon Coast Range. Information obtained from our habitat classification-models can be incorporated into plans to preserve unique riparian habitats maintained by beaverSuzuki and McComb "Habitat classification models for beaver (Castor canadensis) in the streams of the central Oregon Coast Range." Northwest Science. 1998; 72(2): 102-11