Details: For Discovery Center visitors who would like to know a little more about the museum exhibits, Refuge Rambles are ten-minute informal talks on a variety of refuge topics directly related to Discovery Center exhibits. Refuge Rambles topics may include "Geology of the Pioneer Valley," an introduction to the 200 million year old geologic history of the Pioneer Valley, "On the Shape of Shells," a talk about why shells you find on the beach are shaped the way they are, or "Mammals of the North Woods and Their Adaptations." Ramble topics are announced within the museum and are scheduled between 10:00 am to noon on Sundays. For more information, call 413.863.3221 or visit www.greatfallsma.org.