Sheri Williamson, director of the Southeastern Arizona Bird Observatory, discusses the adaptations, continent-spanning travels and intricate relationships of hummingbirds at 7 p.m., Thursday, June 24. Stephen Buchmann gives an illustrated talk on the natural history of bees and discusses the latest findings on colony-collapse disorder at 7 p.m., Friday, June 25. Theodore Fleming presents "Nectar-Feeding Bats and Hummingbirds: Nature's Mega-Pollinators" at 11 a.m., Saturday, June 26. Melanie Lenart presents "Life in the Hothouse: How a Living Planet Survives Climate Change" at 1 p.m., Saturday, June 26. Paul Green presents "Orioles, Woodpeckers and Other Bird Pollinators" at 3 p.m., Saturday, June 26. Events on Saturday, June 26, are free. All other events are free with admission of $7 adults; $5 seniors and active military; $3 students; and $2 for children. Call 742-6455, ext. 228, to register or for more information.