A couple of days ago Dan brought me a surprise: he’d caught a Common Buckeye out in our fields. Buckeyes don’t normally occur here. They’re a southern species that only occasionally strays far enough north to be recorded in eastern Ontario, and nearly all the records are from the southern edge of the province. My mom spotted one last year at her place just fifteen minutes north of the St. Lawrence. It was the first one she’d ever seen. The one Dan brought me was the first one I’d ever encountered, too (perhaps surprisingly, given the time I’ve spent working and traveling in the US). But interestingly, this was actually the second one Dan’s found here on our property this summer (I was away when he found the first one).
The foodplants for this species, such as snapdragons and toadflax, do actually occur in our area. However, like Red Admirals, the adults of this species are not cold-hardy and can’t survive the winters of the northern half of the continent. Instead, the butterflies seen in these areas are migrants that move north from the warmer southern regions. It was a really big spring for Red Admirals this year, possibly because the mild winter we had allowed more to survive than ordinarily do, and perhaps survive farther north than they normally can. I would guess this same weather probably benefitted the buckeyes, too.
It’s been a great summer for butterflies all ’round. In late May and June we were seeing a lot of Giant Swallowtails; they were more common even than our regular Tigers. I posted about Giants before, when we got one last summer. They also don’t normally occur here but will occasionally irrupt north. I’m not sure if they’re also affected by winter temperatures, or if the numbers we had this year were the result of some other factor.