Milkweeds and Monarchs
Late summer in Marin is when we’re all on the lookout for the Monarchs; these regal butterflies are making their way back to traditional over-wintering sites along the California coast, and the real miracle of this migration is that it is not the same individual returning to the site! There are two distinct populations of Monarch butterflies in the United States, and the Rocky Mountains are the dividing line between the Eastern and Western populations. The monarchs we see in the West are over-wintering along the California coast, and during much of the rainy season, thousands of Monarchs are simply hanging in large groups in these special groves of trees. On warm days they may fly a bit, but mostly they are in a torpor. They are also in a reproductive diapause, waiting for days to lengthen and warm up.