The Audubon Society hosts naturalist led walks at 9 a.m. Thursdays. Call 412-963-6100 or visit www.aswp.org to register.

Jennings Environmental Education Center, Route 528, Brady Township, hosts Tom Serfass, professor of wildlife ecology at Frostburg State University in Maryland, at 2 p.m. Sunday for an in-depth look at river otter reintroduction in Pennsylvania. Jennings is open from 8 a.m. to 4 p.m. weekdays and on weekends as scheduled. The trails are open daily from sunrise to sunset. Call 724-794-6011.