October has seen temperatures slightly greater than what we usually expect. Daytime highs and nighttime lows have been a few degrees warmer than normal and as a result, have extended the butterfly season across our area. Butterflies that both hibernate and migrate are still being observed and a couple happen to be records when it comes to late in the year sightings.
Butterflies are cold blooded creatures, meaning they lack the internal capabilities of keeping their bodies at a constant temperature. In order to become active and fly, they require an outside source to warm their bodies. This source is often the sun. Late this past week saw sunny skies and highs in the mid to upper teens, producing some nice butterfly activity.
In order to survive our cold winter, butterflies either hibernate or migrate depending on the species. Hibernation can occur at various stages in their life cycle. Some hibernate as adults, while others hibernate as eggs, larvae, or pupa. As is the case with other hibernating animals, butterflies remain dormant throughout the winter months using very little energy, emerging in the spring when temperatures rise. Monarch Butterflies are well known migrators, as they travel thousands of kilometers in the fall to Mexico, where they overwinter.
According to local records, late sightings were recorded for two species this past week. On October 22, a Milbert’s Tortoiseshell, a species that hibernates as an adult, was reported by a gentleman working in his garden. On October 23, I was happy to report my record sighting of a Painted Lady, a species that migrates, observed in my backyard. The previous record for the Painted Lady was October 21. One day later, I discovered another Painted Lady while walking at Fanshawe Conservation area, breaking my previous day’s record.
To keep track of these record butterfly sightings, or to report your own, join the Middlesex/Elgin/Oxford Natural History Observations Group. If you are looking for more information on butterflies, including help with identification, then I recommend checking out Butterflies of Ontario.
With temperatures expected to remain warm for the next week, more record sightings are quite possible. Butterflies that were still present this past week that are approaching record late observations include: Eastern Comma, Monarch and Cabbage White. The records for these three are October 29, November 5, and November 8 respectively. Check open meadows while out hiking and be observant in your own yard. If you are doing fall yard clean up, be sure to leave any late blooming flowers as lingering butterflies may be attracted to them as a nectar source. If you do happen to come across any of these species, please report them to the group.