Dense marsh is the preferred habitat for the salt marsh harvest mouse.
The salt marsh harvest mouse (Reithrodontomys raviventris) is an endangered species, indigenous to the salt marshes in the San Francisco Bay area. This vulnerable rodent species has become continually scarcer in the wild from the removal of marshes and wetlands in the area. Since 1966, the mouse has existed only within the Bay area, specifically the Vallejo Marshes.
Habitat
Although the species lives in marshes, these creatures build their nests in low shrubs and even sometimes in small trees near a marsh. Scientists named it the salt marsh harvest mouse because it lives in salt marshes and can drink salt water. The species survives on a diet of salt marsh plant stems and leaves, plant seeds and small insects. Finding the mouse can be difficult when considering that it weighs less than an ounce and lives in a wet, dense environment.
Behavior
Salt marsh mice are excellent swimmers and known as solitary except during the mating season. The species has a life span of about a year up to 18 months. The nocturnal creature stays active throughout the year, mostly at night. Known to use other animals' creations as their own, the species will take nests from birds and use other rodents' pathways in the marsh.
The Endangered List
In 1970, the U.S. Fish and Wildlife Service identified the salt marsh harvest mouse as an endangered species. One year later, the State of California also listed the species as endangered; however, a protected habitat has not been designated for this mammal, as of 2004. The salt marsh harvest mouse depends on dense pickleweed salt marsh as its most suitable habitat. The species cannot survive in areas where there is an abundance of fresh water -- areas with high salinity levels are necessary for sustainability.
Reason for Their Decline
The salt marsh harvest mouse species has rapidly declined primarily from the transformation of their natural habitat. The area has become more suitable for humans to live in after draining the wetlands and filling them with earth for development. Industrial and suburban development around the Vallejo Marshes has contributed to 80 percent of the species' environment being destroyed. A U.S. Geological Survey & Western Ecological Research Center study on small mammals in 2004 found not one salt marsh harvest mouse in their traps.
Tags: salt marsh, harvest mouse, marsh harvest, marsh harvest mouse, salt marsh harvest, Vallejo Marshes, endangered species