Northland Nature: Early-season butterflies emerge
Retired teacher Larry Weber, a Barnum resident, is the author of several books, including “Butterflies of the North Woods,” “Spiders of the North Woods,” “Webwood” and “In a Patch of Goldenrods.” Contact him via Katie Rohman at firstname.lastname@example.org.
In late April, we witness several spring happenings that we have expected, as we have seen them before. Ice thaws in wetlands: Small ponds are first to escape from the winter covering, but they are quickly followed by swamps and usually late in the month, lakes will undergo ice-out. (This varies greatly in different years.) We have experienced these in previous years, but they are worth seeing again.
Our list of desired repeats in the spring continues. With the greening of grasses, I also delight in seeing the first dandelions and crocuses in bloom. In the woods, green growth of leeks (ramps) followed by early spring wildflowers, are always a welcome sight. But there is much more.
Several times in recent weeks, I visited the St. Louis River as the opening water expanded. There were plenty of waterfowl. Geese, swans, mergansers and ducks were a delight to observe. Calls of sandhill cranes and red-winged blackbirds came from the shore where herons hunted. In a nearby open space, woodcocks performed their ritual flights at dusk.
None of these were new sights or sounds, but each spring they keep us coming back. As the month continues, I’ll search for phoebes, thrushes, swallows, sapsuckers, sparrows and warblers in yards and hearing frog calls from newly open vernal ponds.
Recently, I found a flock of robins in a field and juncos took over the yard. And I noted the anticipated flock of white pelicans at the river. These large white birds huddled against the cool winds had a black-necked cormorant in their midst. I’ve seen all of these bird news before, but it's worth seeing them all again.
I also walked a trail in the nearby woods. Here, I scared up a butterfly that was basking in the springtime sunlight. Orange and black wings with spots of white, identified as a Compton tortoiseshell. This butterfly with a colorful wingspan of about 2.5 inches is a member of a group called anglewings. Each year (I have never had an exception), an anglewing is the first butterfly to be seen in spring.
The reason for this is that, unlike most other butterflies, they hibernate as adults and are quick to wake and fly on warming days. Other members of anglewings include Milbert’s tortoiseshell, mourning cloak, comma and question mark. The last two are named after markings on wing undersides. In addition to being winter hibernators, they have camouflage undersides of wings. Startled while basking on a tree trunk, they close wings and blend in with the bark.
When it comes to dealing with winter, butterflies run the gamut. Many overwinter as eggs, some as larvae. Others will spend the cold in the pupa stage (chrysalis for butterflies, cocoon for moths). The anglewings hibernate as adults. (Hibernation with insects is often called diapause.) And there are those that migrate; best known is the monarch.
Anglewings choose a site behind bark or beneath boards to winter. (On a fall day once, I watched as a Compton tortoiseshell flew onto the porch and slipped into a crack, not to come out until spring.) Waking early — March, April or maybe even May — they do not have many flowers to visit for nectar. And so, they feed off sap oozing from maples, rotten fruit, animal droppings and maybe pollen from tree catkins.
Later in spring, they mate. The next generation grows up feeding on leaves of birch, willow or aspen and are adults for summer and fall, hibernating later.
Like many other spring things, I’ve seen these early season butterflies before, but they are a joy to see again.