Amanda Miles of South Philadelphia tightens screws on a bird box while Dave Stehman of Conshohocken cleans it out on a Friends of the Wissahickon work day at Andorra Meadow. The previous day a large volunteer crew worked on the bird boxes at Houston Meadow. FOW Field Assistant Varian Bosch who was overseeing the projects and simultaneously training new crew leaders says the boxes are occupied by bluebirds, sparrows, swallows and wrens. Each box is numbered so the birds frequenting the meadows can be tracked from season to season. Watch video of volunteers maintaining bird boxes in the Wissahickon meadows.