We in Southern California area live in a subtropical or Mediterranean climate primarily because of our location on the earth's surface. Southern California is between 30 and 45 degrees north latitude on the west side of North America, with the Pacific Ocean on its western border. The conditions produced by this location are long, hot, dry summers and short, cool, moist winters. This type of climate does not have large amounts of excess water.
These factors have stopped certain plants and animals that require more water from entering our area. They may also determine the course and development of the adaptations on the local plants and animals.
Scanty water, coupled with hot, long summers, restricts animal activity to cool periods, such as early morning or nighttime. The plant or animal habitat and its location may be determined by the physical factors of temperature and moisture. Most animals seek cover where humidity is higher and temperatures are moderate. If animals and plants can withstand the hot summers in this area, part of their battle for survival has been won