Question Mark Butterfly at Rouge National Park

Bob and I had not entertained our youngest son and his wife for quite some time, so in early August, we got together to catch up on all the news.  Not being ones to sit around and visit ad infinitum, after passing a couple of hours on our backyard deck, I suggested a bit of a walk to work up an appetite for dinner.  Cedar Trail at Rouge National Urban Park is close by, and we promised that we would not stand around for hours photographing birds, but the chance sighting of a Question Mark Butterfly did hold us up for several minutes with no complaints from our company.

When first I noticed the orangey-brown profile of the butterfly at rest, I thought it was likely another Eastern Comma Butterfly.  We had seen one a month earlier at Tommy Thompson Park in Toronto.

From its perch on one side of the trail, the butterfly flew down over an embankment on the opposite side of the path and disappeared.  Bob was in hot pursuit while I described to our daughter-in-law how to distinguish between any of the species of Comma Butterflies and a Question Mark Butterfly.  That is when the light bulb went off, and I realized what I had just seen.  In mid sentence, I darted off down the incline, struggled through long, dry grass and pulled up at Bob’s elbow.

In many cases, a Question Mark Butterfly has a diagnostic pearly white “question mark” near the centre of each hind wing, a curved line and a dot that resemble that punctuation mark, but occasionally, the dot is almost indistinguishable or may even be missing.  Then, one must rely on the shape of the butterfly’s wings and its size in order to make positive id.

As the Question Mark Butterfly basked in the sun using a leaf as a perch, the pale violet border on its wings literally glowed.  This behaviour is typical for males of this species in the afternoon.  When seeking a female or defending their territories, male Question Mark Butterflies rest on foliage or tree trunks at that particular time of day.

Question Mark Butterflies create two generations per year.  Eggs are laid in the spring and develop into “summer” adults that have a fly period from May to September.  This generation of adults have hindwings that are mostly black on the dorsal side.  That “summer” generation lays eggs that hatch and develop into the “winter” adults by late August.  The winter form has predominantly reddish-orange on the upperside of the hindwings.

In my estimation, the Question Mark Butterfly that Bob and I saw is of the “winter” form, which can be confirmed by the longer, violet-tipped tails on the hindwings.  In Canada, the fall/winter brood of this species of butterfly may overwinter in a sheltered spot but most likely migrates south and returns again during the spring.

I love how the wings of this species are so angular around the edges, and it is this characteristic that gave rise to another classification for Question Mark Butterflies; they are members of the genus Polygonia, which are anglewings.  When the wings are folded together, the strongly notched outlines of the discreetly textured brown ventral surfaces have the butterfly perfectly camouflaged as a dead leaf.  Thank goodness this individual took flight when we approached, or we might have been fooled into thinking it was a remnant of last autumn’s weathered foliage.  We were thrilled to have seen this beautiful specimen.

Related:

An Eastern Comma Butterfly at Tommy Thompson Park

Frame To Frame – Bob and Jean