Naturalist Robert Ayotte gives an illustrated talk on identifying local trees, shrubs, and vines during winter, with a focus on buds, branching patterns, tree silhouettes, and bark. Followed by a hike. Be prepared for icy trails. 2–3:30 p.m., Eddy Discovery Center, 17030 Bush Rd., Chelsea. $2 (families, $5). Preregistration required by calling 475–3170; space limited. $12 Michigan recreation passport ($17 at the gate) required.