April 22 will mark the 40th anniversary of Earth Day, and people around the country will be celebrating the occasion in all kinds of ways. As for us, we're going to make this Earth Day for the birds. Visit our website to learn about Audubon Earth Day events throughout California, and get some simple ideas for things you can do for this birds this Earth Day (and every day, for that matter). Oh yeah, every day through April 24, on this blog and on Facebook and Twitter, we'll share one of these tips. Today's tip: Put up a bird box and see who takes up residence. (photo by Mike Baird)