Likewise , only five species of birds are resident in this habitat and four are considered rare or endangered .
One endangered mammal is the salt marsh harvest mouse ( Reithrodontomys raviventris ) which occurs in the San Francisco Bay region .
Only five species of birds are resident in this habitat and four are considered rare or endangered .
One endangered mammal is the salt marsh harvest mouse ( Reithrodontomys raviventris ) which occurs in the San Francisco Bay region .