 Two types of amphibians are found in the mounded prairie region , typically around vernal pools . The Pacific tree frog lives in large numbers on the rocks , while tadpoles of the rarer western toad can be seen between March and May . Mammals such as California voles , Heermann 's kangaroo rats , raccoons , and long @-@ tailed weasels can also be found in this region . The western meadowlark and two species of sparrows are the most common types of birds that are seen in the area . Turkey vultures , rock wren , three species of hawks , and other birds patrol the cliffs on the sides of the plateaus . 
