Sharon, Jack and I went to a Bat Talk and Walk put on by the Yolo Basin Foundation. The program began with a 45 minute indoor presentation on bat natural history and included an opportunity to view live bats. The group then carpooled into the Yolo Bypass Wildlife Area to watch one of the largest colonies of Mexican free-tailed bats in California emerge to hunt insects at sunset.
Unfortunately, the bat watching part was a little anti-climatic. It was a very cold and windy evening. Consequently, we got to see some bunches of bat emerge, but not the giant mass of bats that other people have described as witnessing.