Going Green Bluebird House. Join the Green Revolution! Designed exclusively for WoodLink, these beautiful feeders and houses are made from over 90% recycled plastic. They are environmentally friendly and are designed for easy maintenance, large feed capacities, and attracting more birds. All Going Green feeders have powder-coated perforated metal screen bottoms for drainage. Bluebird House 1 9/16 in hole - ideal for Western Bluebirds.