David Brown, a naturalist and animal tracker, will lead an eco-tracking adventure from 9 to 11 a.m. Jan. 21 in the Harold Rafton Reservation. Participants will search for signs of deer, coyote, fox, and other animals. If there is no snow, the focus will turn to other signs of wildlife, such as scat, digs, and burrows. Cost: $18 per person; school-age children must be registered to participate. Warm, waterproof boots or snowshoes and winter gear is recommended. Space is limited. Reserve a spot by registering online on the town’s new website for the Department of Community Services: andoverdcs.com.