What do you think of at the mention of a natural field guide to D.C.? Perhaps red elephants butting heads with blue donkeys, if you’re from out of town, or maybe aggressive pigeons and rats scurrying over Metro tracks. It turns out the city’s forested parks, characteristic rivers, and quaint yards are home to a stunning diversity of flora and fauna, you just have to know what to look for. The National Museum of Natural History is hosting a talk with someone who knows a lot about D.C. nature, Howard Youth, author of A Field Guide to the Natural World of Washington, D.C. [..]