You must be able to prove in court that one or more species is endangered and/or this is the last stronghold for a threatened species. During our field studies (1969 - Present) we have noted a massive decline (even in open undisturbed habitat) in one or more of the reptile species you mentioned. Actualy case file 249 can give you enough information to file for a legal hearing. During this hearing you will need a well spoken expert or experts to testify. If your case is convincing, and can be proven then the development will stop and then it is up to the state to protect the land or not. If they decide to protect the area the developer will be compensated by the state. If they decide not to protect the area then development will continue. There are some things you need to do.
1. Call all southern California Zoos and request information and input from the zoo's herpetologists. Ask for any documentation that will help you. If their views are the same as yours then ask them if they would consider court testimony. Ask for advice.
2. Put calls into newspapers, TV and Radio Channels to publicize the problem.
3. Start a petition drive throughout the county.
4. Get legal representation, and get organized. If development begins picket the site.
5. Call local universities and get information from past studies of the species targeted.
6. Take video to the site and show the current species encountered.
7. Post notices at universities whenever you plan a demenstration or picket. Students love to rally for a cause.
8. Notify envirnmental groups for support.
That is alot to do, but it is the only way you can win. Good luck! If you require any assistance I am in the Temecula area. I can also get you access to case file 249. It is a thirty year history and study of the coastal horned lizard, which is vanishing faster then local frogs. File 249 concludes with a scientific theory for the population decline. It also hammers home that development will finish it off. Whiptails are also taking a beating in many foothill locations. I can help you get tons of information from local studies. Let me know if you need help.