The Last Butterfly
Some butterflies are found flying well into November
November may be known for its gray skies and brown landscapes here in the Northeast, but there are always a few glorious blue days with temperatures rising into the short-sleeve zone. And with those days come the last of the fluttering butterflies. You can find a few Clouded and Orange Sulphurs dancing about the fields, or maybe you’ll run into a camouflaged anglewing — Question Marks and Eastern Commas — adding punctuation to your fine day outdoors. And the truth is, during many Novembers, you might now have a better chance finding them. On average, butterfly flight periods are likely lengthening.
Clouded Sulphur flight season in Vermont from e-Butterfly.org data. Some are found in the Champlain Valley as late as early December.
A recent study in Canada showed that the timing of butterfly flight seasons responded to temperature both across the landscape (variation in average temperature from site to site in Canada) and across time (variation from year to year within each individual site). They found that given the widespread temperature sensitivity of flight season timing, with increased warming we can expect long-term temporal shifts of 2.4 days for every 1.8 degree F change in air temperature for many if not most butterfly species.
Help us document the late season fliers. When you find a November (or even December!) butterfly, snap a photograph and submit it to e-Butterfly.org, a project of the Vermont Atlas of Life. Let’s see who can find the latest butterfly in 2016!