STATUS: Endangered with critical habitat.|
CRITICAL HABITAT: habitat is protected within the San Francisco Bay and the San Pablo Bay national wildife refuges, California Department of Fish and GAme wildife managemetn areas, and a national Audubon Society sanctuary.
DESCRIPTION: Upperparts of mouse are a rich brown which contrasts with the lighter-colored fur of its belly. Its body is 6.9-7.4 cm long with an equal or longer tail. Salt marsh mouse closely resemblethe more common western harvest mouse (R. meglotis).
HABITAT: Salt marsh mouse is endemic to San Francisco Bay Area of California. They inhabit the middle to upper levels of dense pickleweed stand in tidal and diked coastal salt marshes.
Present: Restricted to scattered, discontinuous coastal salt marshes within its original range. Can be found in Contra Costa, Solano, Napa, Sonoma, Alameda, Santa Clara and San Mateo counties. A few are found along the eastern part of the Marin Penisnula in Marin County and Point Richmond in Contra Costa County.
THREATS AND/OR REASONS FOR DECLINE: Land development or flooding has altered much of the that once supported the mice; excessive pumping of water and back filling have eliminated importatn escpe cover for the mice; freshwater discharge from sewage treatment plants has altered some vegetation .
Historic: Originally found throughout the extensive marshes that once bordered San Francisco, San Pablo, and Suisun Bays
OTHER INFORMATION: Salt marsh harvest mice are excellent swimmers, but they become very vulnerable prey to birds when forced into the open. therefore escape cover is usually formed by dense vegetation. Seeds and and green vegeation are their main diet. It acan also drink salt water/ Populations peak in summer and fall. However long breeding season mskes the species particularly vulnerable to extinction. Main goal for saving species is to preserve and restore existing natural habitat.
Life on the Edge. Biosystems Books 1994. Santa Cruz, California