Check out this awesome tool from eNature.com, a site formerly belonging to the National Wildlife Federation (now owned by a privately held company). The tool is called the ZipGuide. Basically, it's a simple search engine....
Last weekend, while hiking (okay, lounging in the sun) in the Tule Elk Reserve in Point Reyes National Seashore, I spotted two white-gray birds circling and dipping overhead. Something about the way they were moving...