You can do the same with knotted plastic mesh. The mesh can be split open if needed and then stitched back together. It will easily keep out hawks. It will keep out racoons as long as they cannot get up in the tree canopy by climbing an adjacent tree.
With a 4 ft x 50 ft roll of welded wire, three wood 2x4x12 and some fasteners you can make a 4 ft x 12 ft x 4 ft high open bottom pen with wood around the bottom perimeter. About $100.
wire
wood
It would cost about the same for 8' x 8' x 4' high.