National Geographic photographer George Grail's slide presentation, "Life on a Wharf Piling in the Chesapeake Bay," takes place at 7 p.m. Saturday at the Howard County Conservancy, 10520 Old Frederick Road in Woodstock. Discover techniques that animals develop for camouflage, reproduction and adaptation to changes in the tides and environment. Call 410-465-8877 or go to hcconservancy.org for more information.