dbk123, I'm glad to hear you are aware, milkweed is the only plant Monarchs feed on. Here in Oregon, I see fewer numbers of them each year. I blame urbanites for ignorantly eradicating milkweed. Milkweed contains a substance that is toxic to birds. They will not eat a Monarch, as they insticntively know it will sicken them. The Viceroy, a similarly colored butterfly, enjoys the same protection from birds, even though it feeds on other plants.