The salt marsh harvest mouse is not the sneaky little rodent that zips into darkened corners when you turn on the lights in your garage.  This golf-ball-sized mouse, as its name suggests, is a salt marsh specialist.  These furry little mice live among the cattails and pickleweed, primarily in tidal marshes associated with the San Francisco Bay.  They make their living by meandering through the maze of vegetation while looking for grasses that produce the seeds they prefer.  When a mouse finds its food plant, it climbs the grass stalk and “harvests” the seeds that grow at the top.  These mice build small nests in vegetation or they may use an old bird’s nest.

Salt Marsh Harvest Mice are incredibly rare.  They are protected by federal and state laws that consider them endangered.  The State of California also considers this species “Fully Protected”, which is the highest level of protection granted to wildlife.  Despite how rare they are, salt marsh harvest mice do live in McNabney Marsh—primarily north of the observation deck.