Union Bay Natural Area (aka Montlake Fill) hosts some 259 different species of birds, everything from the largest swans (with wingspans of 7 feet) to the tiniest songbirds (bushtits, with a wingspan of 6 inches). Some of our birds are so dull they have almost no color at all, though their voices can be very sweet (warbling vireos are a good example). Other birds croak like frogs but glisten like gems (wood ducks). Where did this spectacular diversity come from? The short answer is: from dinosaurs. The long answer is: 150 million years of evolution.

Master birder Connie Sidles describes the latest discoveries of fossil birds and their ancestors, and the most current theories about how birds have evolved from the distant past. Sidles studied paleontology at the University of Chicago and has written four books about nature as she observes it at Montlake Fill.

Cost: $15; $20 after April 13th
Register online or by phone (206-685-8033)