Wildlife ecologist Jeff Keller will lead a walk for Tinicum Conservancy members and friends along the Tinicum Creek as part of the 50th anniversary celebration of Earth Day. The program’s focus will be on bird watching and other wildlife for which the stream habitat is so important. Emphasis will also be on the Conservancy's work to protect the Tinicum Creek watershed, an “exceptional value” state-designated stream and a critical water resource for this area.