Question Marks and Eastern Commas are tricky to distinguish, especially in
winter and early spring, when there is wing damage and when they are seen from a
distance or an awkward angle. These photos of individuals can help
illustrate the differences: Question Marks have purple borders in cold
weather while Eastern Commas have 1) shorter tails on their hind wings, 2)
rounder, fuller wings in the summer and 3) more prominent marginal spots on
their hind wings in the winter. Also, Eastern Commas are more likely
to spread their wings and stay in place: it's tough to get a good dorsal view of
the Question Mark or a good ventral view of the Eastern Comma.
Dorsal Views
Eastern Comma (Polygonia Comma), NC Botanical Garden,
4/22/04. They are much less common than Question Marks, and don't
seem to change their appearance in the Piedmont, where they show up
mainly in the spring.
Summer form Eastern Comma, Johnston Mill Nature
Preserve, Orange County, NC, 6/9/07. The darkened hind wings are
typical of summer individuals.
Winter form Question Mark
(Polygonia interrogationis), Penny's Bend Nature
Preserve, Durham County, NC, 2/9/08. Part of the right hind wing
is hidden in shadow. Note the purple border, typical in the colder
months.
Eastern Comma, Occoneechee Mountain Natural
Area, Orange County, NC, 3/13/06
Summer form Eastern Comma, Johnston Mill Nature
Preserve, Orange County, NC, 6/9/07. The darkened hind wings are
typical of summer individuals.
Eastern Comma, Boone, Watauga County, NC, 8/31/05.
You can see a white comma-shaped marking in the middle of the hind wing,
although it's next to something that looks like a period!
Eastern Comma, Raven Rock State Park, Harnett
County, NC, 3/12/06. Again, a "period" and a "comma."
Question Marks and Iridescence
You've probably heard the word "iridescence" thrown around to
describe bright, shiny objects which glitter in the sun -- such as
the blue-green hairs on the back of long-tailed skipper (but we'll
cover that later). Iridescence, though, means color that changes
with the angle of light on a surface.
I've heard that the only true pigments are brown and black, and that
all others are the result of reflection and refraction. A close
look at butterflies makes this very believable!
First, an example of completely deceptive color: a picture of a
butterfly in flight that might have been mistaken for a fairy under
other circumstances:
Don't those wings look like something out of an old children's book? Still, you have to wonder how the fairy's monstrous head got overlooked.
And now, two more typical instances of mimicry: Let's look at the
Question Mark (Polygonia interrogationis):
When light shines on the ventral side of a
Question Mark, it looks like a dead leaf. This seems appropriate for
11/1/2003, the date this photo was taken, when the trees were still
full of brown leaves.
However, when the same butterfly is
backlit, the pattern on the dorsal side of the wings shows through.
Presumably, this causes camouflage to take a back seat to the mating
process.
Question Mark, Penny's Bend Nature
Preserve, Durham County, NC, 3/14/07. You can see the white
"question mark" pattern in the middle of the hind wing (actually, a
backwards "c" and a dot under it). You can also see the dorsal side
pattern of the wings in the picture on the right because the butterfly
opened its wings.
Here are some other pictures of Question Marks,
illustrating how their wing patterns change with the time of year.
Question Marks come out before the other butterflies in my part of North
Carolina, and they don't need especially warm weather to fly fast and high.
Question Mark, Indian Creek Wildlife
Observation Trail, Chatham County, NC, 4/4/06
Durham, 10/13/05.
Another fall form, also with blue wing borders.
Fall form, Duke Gardens, 10/17/03. Hind wings look
more like forewings this time of year. Note the blue wing borders.
Eno River SP, Old Cole Mill Rd. access,
Durham, 2/28/06. This was one of 11 Question Marks flying
frantically through the park.
Question Mark, NC Botanical Garden, Orange County, NC,
3/14/06. You can see a white marking in the middle of the hindwing
that looks like a sideways question mark, but it also looks sort of the
like the period- and comma-like markings on the Eastern Comma.
Nevertheless, the multiple light-colored bands on the Eastern Comma's
forewing set them apart.
Question Mark,
ventral view. You can see the white "question mark" on the hind
wing. Mason Farm Biological Reserve, Orange County, NC, 5/20/11
Durham, 8/23/03. This Question Mark is dressed for
summer.
Durham, 10/12/03. You can see some darkening here,
but it's not quite at the dead leaf stage.
Durham, 10/13/05. Same butterfly as the one above for this date.