Natural History of Orange County, California Compiled by Peter J. Bryant, School of Biological Sciences, University of California, Irvine, Irvine, CA92717

Orange County is the smallest county in Southern California, with a total land area of 789 square miles, but its population of over 3 million people makes it the second most populous county in the state, with the highest population density (3822 persons/square mile in 2004) outside of San Francisco County. Yet, as part of the California Floristic Province, one of the world's Biodiversity Hotspots, it retains an impressive flora and fauna, and the southern part of the County still includes large, relatively undeveloped sections of coastal sage scrub habitat that have been recognized in the Orange County NCCP (Natural Communities Conservation Planning) process. 37,000 acres have been designated as a National Natural Landmark. Orange County contains significant populations of rare and endangered species of plants, birds and mammals. It is home to over half of the remaining population of coastal cactus wrens, and to over 15% of the remaining population of the California gnatcatcher, the country's largest contiguous population of this threatened species. In view of the huge rate of destruction of natural habitats in the County, we are probably losing countless species of less conspicuous animals and plants before they are even documented. This web site is an attempt to catalog and appreciate the biodiversity of Orange County by compiling data and photographs from as many sources as possible. Organizations

Species	Habitats
Arthropods (Insects, Spiders and their relatives) Cnidaria (Sea Anemones, Jellyfish, and Hydroids) Molluscs Echinoderms Fish Amphibians Reptiles Pacific Pond Turtle, Clemmys marmorata Birds Avifauna of Upper Newport Bay, California Mammals A checklist of the animals of the Santa Ana Mountains Plants	California Wildlife Habitat Relationships Coastal Mountains California's coastal mountains Chaparral California Chaparral Field Institute Coastal Sage Scrub Restoration Ecology at UCI Natural Community Conservation Planning The Irvine Ranch Land Reserve Streams and Rivers Introduction to Orange County Watersheds Marine Terraces California's Marine Terraces Bluffs and Headlands California's Coastal Bluffs Coastal Sand Dunes California's Coastal Sand Dunes Beaches California's Beaches Wetlands California's Wetlands California's coastal wetlands Wetlands and Wildlife Care Center of Orange County Rocky Intertidal Intertidal Life of Orange County, California California's rocky intertidal zones Islands and Offshore Rocks California's Islands and Offshore Rocks Nearshore Waters and Open Ocean California's Nearshore Waters and Open Ocean
If you want to help develop this site, or if you have comments or suggestions, please contact: Dr. Peter J. Bryant (pjbryant@uci.edu) School of Biological Sciences University of California, Irvine Irvine, CA 92717, USA Phone (949) 824-4714 Fax (949) 824-3571