As a naturalist, you learn to look for things in places others may not look. Sometimes, we look for things in places others don't want to look. This is such a moment...
Yesterday, I was hiking along a trail and found some scat. This story isn't about the depositor or the contents of the scat, though it was domestic dog (Canis lupus familiaris) left by an idiot owner too irresponsible to pick up after their pet. I'll save my full feelings on that for another installment. Instead, this is about the animals attracted to scat. Sure, we all know insects such as flies and beetles are attracted to scat. But, this time, a familiar and beautiful butterfly was sitting atop the dog scat.
The Question Mark Butterfly (Polygonia interrogationis) feeds on nutrients in scat. The distinct sideways silver-white question mark found in the middle of the underside of the hindwing, seen in the photo above, gives this beautiful butterfly its common name.
(Click to enlarge)
Belonging to the group of butterflies we call anglewings, The Question Mark Butterfly (Polygonia interrogationis) owes its scientific name to both the "angles" of its wings and the punctuation mark found on its hindwing. As we remember from elementary school, polygons have many angles and a question mark ends an interrogative statement. Well, (Polygonia interrogationis) literally means having many angles and asking a question! The Question Mark can be differentiated from a close relative, the Eastern Comma Butterfly (Polygonia comma), by the period dotting the question mark on the hindwing. Without the period dotting the question mark, the Eastern Comma only has a comma on its hindwing. (Be careful, as the occasional Question Mark has a reduced period dotting the question mark!) As I've said during many nature walks and natural history classes, the anglewings look almost like pieces of a jigsaw puzzle with their uniquely-shaped wings. This jigsaw appearance is more than nature's artistry. When they sit with folded wings, they look very much like a dried and dead leaf from a tree.
Green Comma (Polygonia faunus) for comparison. Note the lack of period under marking. I spotted this lovely butterfly while hiking in Coeur d"Alene National Forest, in Idaho. It is lapping up nutrients from what appears to be old Mountain Lion scat.
The most common larval food plants for the Question Mark Butterfly are American Elm (Ulmus americana), Winged Elm (Ulmus alata), Hackberry (Celtis occidentalis) and Sugarberry (Celtic laevigata). Hackberry trees are an incredibly common tree in this area, in yards, parks and undeveloped areas. The caterpillars are pretty amazing, with their many spines along the length of their bodies. As soon as I get good photos of a caterpillar, I'll be sure to post them. The range of this gorgeous butterfly is just about the entire United States east of the Rocky Mountains, so many of my subscribers are very likely to encounter this species. (Sorry Montana, Utah and other subscibers west of the Rockies! You guys have your own beautiful butterflies that aren't seen east of your locations.)
The many angles of the wings of a Question Mark Butterfly (Polygonia interrogationis).
(Click to enlarge)
The many angles of the wings of a Question Mark Butterfly (Polygonia interrogationis).
(Click to enlarge)
Now that we know the butterfly and its hosts, let's look into why a butterfly would be feeding on scat and not the nectar of a flower. Many butterflies will seek nutrients, like salts and minerals, in wet areas on the ground. This is known as puddling. It isn't uncommon to see dozens of butterflies lapping up nutrients in the sandy soil next to a seepage area in the sandhills and coastal plain of the Carolinas. Likewise, many butterflies actively seek out rotting fruit, scat and even carrion to find fairly abundant sources of nutrients and minerals. The Question Mark will utilize all of these and will usually only feed at flowers as a final choice.
Let this be a lesson in how beautiful things in nature use things we may find repulsive and disgusting. Let's also remember that anyone who doesn't pick up after their pet in public places is an idiot. Wait... I said I'd save that for another time.