Calling all local birders! Ornithologist Dr. Andy Mack will present a birding talk on “Fall Migration” at the Bellbrook headquarters of the St. Xavier Nature Preserve. This evening lecture will be followed on Saturday, September 28, by a guided bird walk from 7:00 to 10:00 AM through the fields and forests of St. Xavier.  This is the third of four “Birds Across the Seasons” paired events presented by Dr. Mack.  All events are open to the public and free to attend.