In March and April, while the snow is still melting from the landscape in Maine, a handful of hardy butterflies emerge to soak up the sun. Often flying on tattered wings, these delicate, colorful harbingers of spring wake before the trees even begin to bud.
Mourning cloaks are among the first to stir. With large, dark wings edged in pale yellow and adorned with blue spots, these butterflies are hard to miss. On warm days in March in April, they flutter through the forest and perch in the sun, wings open wide.
“It always warms my heart to see a mourning cloak in the spring,” said Phillip deMaynadier, a biologist who specializes in butterflies at the Maine Department of Inland Fisheries and Wildlife. “I know there are a lot of signs of spring, but there’s something about how delicate and beautiful these little wispy creatures are. After such a harsh season in the north woods, it reminds me how resilient life is.”
Butterflies have different strategies for making it through Maine’s tough winter. Many species overwinter in their caterpillar (larva) form. Others overwinter as eggs or chrysalis (pupa). Some overwinter as adults but migrate south, such as the monarch butterfly. And a small number of butterflies overwinter as adults while remaining in Maine, tucked away in some sort of shelter as snow and ice piles up around them.
These butterflies find shelter in a variety of places, including tree hollows, under pieces of flaking tree bark, in cracks between rocks and under the shingles of buildings. Late last fall, deMaynadier watched one butterfly nestle itself between boards on the outside of his barn.
“It’s a nice reminder of just how many species of butterflies are all around us all the time,” he said. “Close to 100 species of butterflies are out there right now (not counting the migrant species), alongside you as you walk through the woods and fields. They’re just hidden as eggs and pupa and caterpillars in most instances.”
Of Maine’s 118 recorded species of butterflies, just eight species — including the mourning cloak — overwinter in Maine as adults to emerge in early spring, deMaynadier said. And all eight of those species belong to the same family: the brush-footed butterfly family.
In addition to the mourning cloak, there’s the tortoiseshell butterflies, of which there are two species: the Milbert’s tortoiseshell and Compton tortoiseshell. Both have striking black and orange patterns on their wings. (It was a Compton tortoiseshell that deMaynadier watched tuck itself away on the outside of his barn last year.)
Then there are the comma butterflies: the eastern comma, gray comma, hoary comma, green comma and satyr comma. With notably ragged edges to their wings, these butterflies display orange, brown and gray patterning and are hard to tell apart.
“[Comma] is a very useful and appropriate name,” deMaynadier said. “Every single one of the commas I listed for Maine has a little, delicate, silvery comma mark on the middle of the hind wing, underneath.”
With the land still half in winter’s grasp, there aren’t any flowers for these early butterflies to draw nectar from. Instead, they feed on tree sap that oozes out of tree wounds, such as the holes drilled by woodpeckers. You can also often find them flying around at maple sugar operations, where sap is drawn out of trees to make syrup.
They also feast on rotting fruit such as old berries and apples lying on the ground from last fall. And they gain nutrients from animal feces and carrion.
Because these eight butterflies overwinter as adults, they have by far the longest lifespans of all the butterfly species that overwinter in Maine. (The migrant butterflies, such as monarchs, also have long lifespans.)
“When you think about it, they’re going into cavities and wood sheds in October and November, and they’re not coming out until now,” deMaynadier said. “And they’re not done. Now that they’re out, they’re going to breed. This generation will expire here over the next month or so, but that still makes them about 8 months old. That’s a really long lifespan for a butterfly.”
Other spring butterflies in Maine, such as the spring azure and cabbage white, overwinter in pupa form. They’re commonly spotted in April and May.
“Anything that overwinters as a pupa is going to be the next earliest group people would likely encounter because they have a headstart on the butterflies that are in egg or larva form,” deMaynadier explained.
A number of species of elfin butterflies, which overwinter as pupa, emerge in April, deMaynadier said. In that group are the brown elfin, hoary elfin and eastern pine elfin.
“They tend to be small and kind of drab but energetic little butterflies, about the size of your thumbnail,” deMaynadier said. “They have subtle, intricate brown and black patterns on their wings.”
In order to spot them, you have to keep your eyes peeled, deMaynadier said, but they’re fun to watch. And if you happen to get an up-close view of one, they have an understated type of beauty.
So be on the lookout for butterflies this spring. As the world wakes, these delicate creatures are among the first to bask in the sun, and more will emerge as the days warm.