The Juvenal’s duskywings coloration is perfect for camouflage on sand and
mudpuddles. Its spots look like grains of sand and the dark like the mud.
Photo: J. Morton Galetto
In these last weeks of April, I have spent my mornings in the pine-oak woods of the pine barrens. As I sit quietly in a blind at 5 a.m. I’m alerted to morning’s arrival by the dawn song of many birds, including turkeys gobbling on their roosts. My head bobs as I fight sleep and a gobble jolts me to be alert.
Cardinals, blue jays, oven birds, fish crows, and red-headed woodpeckers begin to dominate the soundscape as the sun rises. Add to their calls chipping and song sparrows, eastern towhee, dark-eyed junco, pine warbler, tree swallow, summer and scarlet tanager, goldfinch, bluebird, prairie warbler, great crested flycatcher, gnat catchers, and Carolina chickadees. At one point even a southern gray tree frog chimes in on the cacophony. I wish I could say I know all these common songs by heart, but alas, I often have to rely on Cornell Institute of Ornithology’s Merlin application to assist me.
The mornings have been brisk and when the eastern towhee sings his “Drink your tea-e-e-e-e,” I wish I’d packed a thermos, and I “wee-eep” with the great crested flycatcher—as I feel the chill of a spring morning in my aging bones. These are onomatopoeic representations of these birds’ calls, letters or sounds that attempt to mimic the way a bird vocalizes, most of which I get hopelessly mixed up. I’ll spare you the details, lest you make the same wrong associations.
As things begin to warm up, I leave the blind for some walkabouts and discover that our solar-powered friends the butterflies are now up to their nectaring and courting. Our early emergent neighbors are showing off; primarily I see eastern-tailed blues and duskywings. It’s early spring and I believe the duskywing I am noticing is the Juvenal’s duskywing. Once temperatures reach the 50 to 60 degrees Fahrenheit and nighttime lows remain above freezing, you begin to see the early species.
The duskywing is one of the little brown jobs of the butterfly world—an early emergent and only on the scene for a short time. At first I thought there might be a “population explosion” or “irruption year” of them, like the masses I saw of red admirals in 2021. But as I read more about their life history and habitat I realized I was simply in the right place at the right time.
Adults fly in springtime beginning in March and are visible only until about mid-May. There is just one brood in a year. Females will lay their eggs singly on oak leaves. The caterpillar is a pale to yellow waxy green with a pale stripe that runs the length of its body. The larva is slow-growing, taking the entire summer to mature. Caterpillars are an important food source for juvenile birds and all stages of butterflies provide food sources for predators.
Pat and Clay Sutton describe the duskywings as a species that exhibits patrolling behavior. They seek out females and get into dogfights with rival males. The Suttons further note that they especially like guarding the sandy roads of oak woods. Gochfeld/Burger describe their habitat as “widespread, particularly cuts and edges of oak and pine-oak woods.” They elaborate, “As one drives along dirt roads, groups of these butterflies are disturbed from their basking and they fly up, only to resettle quickly as one passes.” This was the behavior exhibited as I walked, by both the duskywings and eastern-tailed blues.
Duskywing caterpillars eat primarily oak leaves. The three orange spots on either side of its head against a light to deep orange background are one identifier. Also the subdorsal stripe. Photo: Canadian iNaturalist hannerbananer
A duskywing “puddling” for moisture, salts and nourishment in the crevasse of a primarily dried up puddle. When many butterflies gather at the same small pool it is sometimes called a “mud-puddle party (Sutton).” Photo: J. Morton Galetto
Duskywings are specialists like most butterflies and their larvae prefer oak leaves. Lepidopterist David Wagner notes that naturalist Bob Barber found them to eat hickory as well in New Jersey. This galvanized my attention during my readings because I knew Bob when he lived in New Jersey and worked at the Haskin Laboratory in Port Norris. He was the brother of famed local journalist Jean Jones. Both were extraordinary in their love of natural history and Jean was also a genealogist and historian. So reading about Bob’s contribution to the knowledge of duskywings brought back fond memories.
On my walks I noticed that duskywings also took an interest in scat and puddling. Compacted areas in sandy roads that hold moisture are often an oasis for butterflies that seek moisture, nutrients, and salts from these sources. Rotten fruit, carcasses, and sap offer some of the same nutritional qualities.
I surmise the duskywing that I observed to be Juvenal’s, versus the similar Horace’s or sleepy duskywings. In appearance both are similar, especially to the untrained eye, but from photos and descriptions of early spring abundance Juvenal’s is my guess. Horace’s are much less common.
Close-up duskywing’s head and antennae. Butterflies in the skipper group are distinguished by antennae that have hooked or recurved tips. Photo: J. Morton Galetto
The Conservation Commission of Missouri and Gochfeld/Burger both speak of time of year as being helpful for identification of Horace versus Juvenal’s. “Emergence time is a big clue: Although both are present in springtime, Juvenal’s duskywing is no longer present after about mid-May. Specimens found after mid-May will be Horace’s duskywing.” (Conservation Commission of Missouri)
Duskywings are in the superfamily of Papilionoidea (butterflies) but they are also skippers, having hooked antennae and furry bodies. Unlike moths who also have furry bodies, they fly during the day and are considered true butterflies. They have an overall look of being brown or gray brown, although with closer inspection, using binoculars, you can see spots on their wings and a bordered fringe of lighter buffy tans.
One outstanding feature on the male is the costal fold along the leading edge of the forewing. This contains specialized scales that emit pheromones (sex scents) that attract females—his version of “Old Spice.”
They are spread-winged skippers, meaning that when at rest they have their wings open. This makes it easy to view their upper wing, but it is difficult to catch a glimpse of the lower side without netting one.
Having duskywings dash about my feet as a spring day warms up adds fascination to each step. I am not so self-absorbed as to think that nature was created to amuse or serve us, but surely it delights me just the same. These flights will soon be ending and other butterflies will be emerging. Try and catch some looks at the duskywings while they are still flying about.
What’s in a Name?
The names Juvenal and Horace derive from Roman literature, where these two notables were ancient Roman poets/satirists. Decimus Junius Juvenalis (55-128 AD) is responsible for the phrases “rare bird” and “a sound mind in a sound body.”
In the 1700s and 1800s it was fashionable to label flora and fauna with names from Greek and Roman literature since these were hallmarks of an educated person. Swedish biologist and physician Carl Linnaeus (1707-1778), considered the “father of taxonomy,” imposed classification systems on the natural world. By providing living things with scientific names drawn from Latin and Greek, he allowed scientists to use the same terms across the different modern languages that they speak—thus distinguishing the species they are referencing.
His student Johann Christian Fabricius carried on his work and named the Juvenal’s duskywing (Erynnis juvenalis) in 1793. Scudder and Burgess carried on the literary reference in 1870 in naming the Horace (Erynnis horatius).
Sources
How to Spot Butterflies, Patricia Taylor Sutton and Clay Sutton, 1999.
Butterflies of New Jersey, A Guide to Their Status, Distribution, Conservation and Appreciation, Michael Gochfeld and Joanna Burger, 1997.
Caterpillars of Eastern North America, David L. Wagner, 2005.
Missouri Department of Conservation, Field Guide on-line, Juvenal’s Duskywing.
