Lanman C.W.,Institute for Historical Ecology |
Lundquist K.,Occidental Arts and Ecology Center Institute |
Perryman H.,Worth A Dam |
Asarian J.E.,Riverbend science |
And 3 more authors.
California Fish and Game | Year: 2013
The North American beaver (Castor canadensis) has not been considered native to the watersheds of coastal California or the San Francisco Bay Area. These assertions form the basis of current wildlife management policies regarding that aquatic mammal, and they date to the first half of the 20th century. This review challenges those long-held assumptions based on verifiable (physical) and documented (reliable observational) records. Novel findings are facilitated by recently digitized information largely inaccessible prior to the 21st century. Understanding that beaver are native to California's coastal watersheds is important, as their role in groundwater recharge, repair of stream channel incision, and restoration of wetlands may be critically important to the conservation of threatened salmonids, as well as endangered amphibians and riparian-dependent birds.
Lanman R.B.,Institute for Historical Ecology |
Lanman R.B.,OAEC WATER Institute |
Perryman H.,Institute for Historical Ecology |
Perryman H.,OAEC WATER Institute |
And 4 more authors.
California Fish and Game | Year: 2012
The North American beaver (Castor canadensis) has not been considered native to the mid- or high-elevations of the western Sierra Nevada or along its eastern slope, although this mountain range is adjacent to the mammal's historical range in the Pit, Sacramento and San Joaquin rivers and their tributaries. Current California and Nevada beaver management policies appear to rest on assertions that date from the first half of the twentieth century. This review challenges those long-held assumptions. Novel physical evidence of ancient beaver dams in the north central Sierra (James and Lanman 2012) is here supported by a contemporary and expanded re-evaluation of historical records of occurrence by additional reliable observers, as well as new sources of indirect evidence including newspaper accounts, geographical place names, Native American ethnographic information, and assessments of habitat suitability. Understanding that beaver are native to the Sierra Nevada is important to contemporary management of rapidly expanding beaver populations. These populations were established by translocation, and have been shown to have beneficial effects on fish abundance and diversity in the Sierra Nevada, to stabilize stream incision in montane meadows, and to reduce discharge of nitrogen, phosphorus and sediment loads into fragile water bodies such as Lake Tahoe.