Walking home from the library this afternoon, I saw two sulphur butterflies fluttering in grassy areas on two separate blocks. My eyesight generally doesn't allow me to get positive IDs of two-inch insects several feet away, so I had no idea which of the many varieties of sulphurs these were. My first reaction to the little guys was sadness, as there were no nectar plants in bloom that I could see--not even dandelions, which do occasionally throw up winter blossoms in our area--and I hate the thought of butterflies (or anything else) starving and freezing.
An online search revealed that what I saw was probably the common clouded sulphur, which flies in our area as late as December. Unfortunately, the adults that I saw are unlikely to last much longer; sulphurs overwinter in the chrysalis or egg stages, not as adults. Another possibility is that at least one of today's butterflies was a cloudless sulphur. Every year, some of these beautiful but ephemeral creatures do a reverse migration: instead of flying south as do the monarchs and most of their fellow Phoebis sennae, they fly north, some of them actually arriving in Canada before winter sets in. Unfortunately, this is their last flight, as they do not survive the winter. No one seems to know a reason for this behavior.
Doomed as they are, today's butterflies were still beautiful.