Dark butterflies of midsummer
As we exit this summer month of July, we can look back at these 31 days and yes, we've seen what this month is famous for. The Northland experienced several very hot days where we heard heat index warnings instead of wind-chill warnings. We also hosted a couple of impressive storms, some giving plenty of rain and others with hurricane-force winds. The storms also gave quite a display of lightning. We will remember this turbulent month.
A little less dramatic during this month, we have also been getting shorter daylight times each day. With a sunrise at about 5:45 a.m. and sunset at 8:45 p.m., the daylight of 15 hours is now much less, nearly an hour, than what we had when we began the month. According to the calendar, the first week of August is midsummer.
It is the sunrise-sunset times and not the stormy hot weather that brings a response with the birds. Though I still hear a few persistent singers — red-eyed vireo, wood peewee, indigo bunting, yellowthroat and a few sparrows — most have quieted for the season. Newly fledged family units move among the branches and most of the sounds we get now are chips instead of songs. Some families form groups and a few are taking that next step of early migration, most notably the swallows and shorebirds. And then there are the goldfinches that use the recently formed thistle-down seeds to make their nests as they settle down to raise a family at this late date.
The thistles are going from flower to seed, what many plants are doing now in late July. Milkweeds, fireweeds, evening primroses, Michigan lilies, bergamot and purple-fringed orchids may still be blooming, but a whole new set of wildflowers associated with mid- to late-summer—especially August—are joining the bouquet. These include yellows of sunflowers and goldenrods with whites and purples of asters. I have found several species of each flowering now; more to come.
The ripe berries have moved on from the strawberries to blueberries and raspberries to juneberries and pin cherries. Sugar maples and mountain maples are dropping their ripe whirling samara seeds. And each day, a walk in the woods reveals new mushrooms that have popped up.
But in some recent hot days, it was the insects that I found so abundant and interesting. At deer fly and horse fly time, blended with the latest kinds of mosquitoes, it is a little difficult to appreciate these six-legged critters, but if we persist, there is much more to see. During some recent biking, I heard the crickets from the ground level while cicadas called from the trees. Grasshoppers, katydids (also soon to be calling) and locusts hopped and flew along the trail. Bees, flies, wasps and hornets were at the flowers. Predacious dragonflies with their smaller damselfly cousins were hunting here as well. And butterflies are also present.
Without a lot of searching, I was able to locate 10 kinds of these colorful insects. Orange seemed to be the predominate color among the monarchs, fritillaries (three kinds), northern crescents and the tiny skippers. There were a few basking and feeding black and white white admirals and red and black red admirals. Flittering about were white cabbage and yellow sulphur butterflies. And flying here too were some that looked all dark.
We usually expect butterflies to be very colorful. Indeed, they have been called "flying flowers," not brown or black. But several species of butterflies in our region are more drab. Earlier in the summer, I noticed several brown ones carrying names like little wood-satyr, ringlet, eyed brown and northern pearly-eye. Now, at a later date, I add one more to the list: the common wood-nymph.
This wood-nymph is one of the last to appear in the region. They are residents of the open spaces, but I tend to find many at the woods' edge. Wings are all brown, ranging from light to dark, with a couple of light dots, called eyespots, on the wings. (Eyespots are frequent on wings of butterflies and moths and though they do not give any sight to the insects, they do help to deter predators.) Common wood-nymph are midsize butterflies with wingspans of about 2-3 inches.
We usually do not see them in this spreading pose since they feed on flower nectar and bask with wing closed, what is referred to as lateral basking. Frequently when first seen flying by, they appear all black, but a closer look or in better sunlight, shows them to be more of a dark brown. The ones that I saw were all dark colored, but some have a white square-shaped spot near the eyespot.
As with much of nature as we enter August, the arrival of these dark butterflies tells of the season moving on. I expect to see more of these and other insects in the coming weeks of mid- and late-summer.