Recovery Plan for the Northern Spotted Owl - DRAFT

Sacramento River Canyon now provides a 10- to 13-mile division betweenknown owl sites in the California Klamath and Cascades provinces. A narrowband (about 20 miles wide) of low-density owl habitat provides an obstacle toowl movement between the California Cascades and the northern SierraNevada. While there are forests in some of these gaps, habitat quality and owldensities in these areas are low. These conditions may be sufficient to ensuregenetic connection, but probably limit the amount of demographic support thatcould be provided by adjacent provinces.Predation and Competition. Great horned owls naturally occur throughoutthe province because of the open forest condition and the history (more than50 years) of large-scale habitat modifications in the province. Fire suppressionprobably has resulted in the exclusion of great horned owls from some foresthabitats that are now denser than they were historically.Barred owls were first identified at two sites in the province in 1991. Thecurrent competition from barred owls is probably low, but is potentially detrimental,especially for this sparse and high-risk spotted owl population.Vulnerability to Natural Disturbance. Fire is the major natural disturbancelikely in the California Cascades province. Fire may not be as great a problemas in the Klamath province, because of the presence of areas of naturally poorsoils and sparser vegetation. However, fire probably affected the compositionand structure of the historic forest. Fire suppression during the last 70 to 100years probably has increased vulnerability of the forest to wildfires. Winddamage is a minor problem, but drought and insect/disease problems are ofconcern.64