California is one of the most biodiverse regions in the world, with more than 30,000 species of insects, 6,500 plants, 650 birds, 220 mammals, 100 reptiles, 75 amphibians, 70 freshwater fish, and 100 species of marine fish and mammals. We celebrate the unique diversity of living things found in our state, and encourage actions to protect them, on California Biodiversity Day, held Sept. 7 of each year.