Several additional sensitive species occur on the Reserve at some time during the year. In total about 40 species considered sensitive are found on the Reserve. Herpetiles are very abundant on the Reserve. Birds are especially plentiful in the Reserve. Lake Mathews serves as a major stopping-off spot along the Pacific Flyway, and ducks and other migrants abound.
Excellent opportunities exist for the study of the threatened coastal California gnatcatcher.
The Reserve is mostly dominated by two types of plant communities. Non-native annual grasslands abound, especially in the flatter, northern portions. These grasslands vary in thickness from year to year depending upon rainfall. Being counterproductive to the welfare of the SKR, these grasslands are a major focus of our habitat restoration efforts through prescribed fires. The other primary habitat found on the Reserve is Riversidian Sage Scrub, a highly xeric form of coastal sage scrub.