This kangaroo rat lives in the Santa Cruz Sandhills of California and gets its name from its distinctive large hind legs. In the past, this rare animal could be found in the mountains south of San Francisco, but populations been pushed to a single parcel in the Santa Cruz Mountains. One of 23 subspecies of kangaroo rat found in California, the Santa Cruz variety is under a real threat of extinction because of dwindling populations and health problems stemming from low genetic diversity. Their loss would be a withering blow to Santa Cruz mountains — the kangaroo rat is known as a keystone species that support many other species; its loss would send a ripple of damage through the entire food web.