Woodpeckers made some awful 1/2-in.-dia. holes in my red-cedar sidewall shingles. After replacing more shingles than I care to admit, I came up with an easy, effective solution. I simply cut 1/2-in. tapered plugs from new pieces of shingle with a plug cutter mounted in a drill press. I then clean up the pecked hole in the shingle with a spade bit, insert the plug with a bit of waterproof glue, and tap it into place.
To discourage the woodpeckers from doing more damage, I hung reflective spinners under the eaves. The spinners turn in the breeze, reflecting light and keeping the birds away. This technique has helped to solve a frustrating problem.
Tom Sabellico, Woodbridge, CT