This hardy butterfly is slightly smaller than the Monarch and can be recognized by the deep maroon-brown color of its upper wing surfaces and contrasting wing borders with ragged edges. The wing borders vary from yellow to white across the species’ range, and are usually cream-colored in my Southern Michigan area. The wings also include rows of iridescent blue spots just inside these borders that remove any doubt about the butterfly’s identity.
Mourning Cloaks emerge earlier in the spring than other butterflies because they overwinter as adults instead of as caterpillars or chrysalises. They do this by hiding in a hollow tree or other shelter after secreting chemical compounds into their bodies that prevent ice from forming in the tissues. The Mourning Cloak is one of a small number of native butterflies that overwinter this way, and the process is technically known as cryo-preservation rather than hibernation.
They typically mate here in late April or May, and the females lay clusters of eggs on the twigs of a willow, aspen, cottonwood, birch, or elm tree. Both sexes die soon afterwards, but the nine to eleven months that they live is one of the longest life spans of any North American butterfly. And the eggs that they leave behind hatch into caterpillars that change into butterflies in mid-summer and perpetuate the species.
Mourning Cloaks obtain most of their nourishment from tree sap, and this is normally readily available when they awaken and need quick food in the early spring. They also consume flower nectar and feed on mushy fruit when they can find it. Some butterfly enthusiasts take advantage of this sweet tooth and attract them to their yards with ripe bananas, rotting apples, or a variety of special recipes.
Mourning Cloaks also have to bask regularly to function in cool weather, and their dark colored wings make natural solar collectors. My sunny yard attracts a couple of them every year, and they look like pretty yard ornaments absorbing solar heat with their wings spread wide open. However, they can fold their wings together and look like a dead leaf or piece of tree bark in an instant if someone gets too close.
Many readers are probably wondering how the Mourning Cloak received its haunting name, and this story is as unusual as the butterfly. While the species inhabits all of the northern continents the association with the garments known as cloaks practically guarantees that its name originated in Europe during the Middle Ages. And linguistic evidence indicates that this probably happened in present-day Germany or Scandinavia. In fact, the German, Swedish, and Norwegian names for the species all translate into Mourning Cloak.
Many aspects of medieval life in this region are still mysterious, and the butterfly helps fill out the picture. It tells us that some Germanic or Norse people wore special cloaks to mourn the death of loved ones, and that these cloaks were probably dark brown with light trim. They began calling the butterfly Mourning Cloak because of its resemblance to these cloaks, and the name caught on throughout the region. Then German and Scandinavian immigrants found the same butterfly in North America, and almost certainly introduced the name here.
While the Mourning Cloak is frequently described as a woodland butterfly, it also thrives in city neighborhoods that provide the necessary food and shelter. It was the most common large butterfly in the Lansing neighborhood where I grew up, and we saw some in our yard every year. In other words, our rural, suburban, and urban readers could all see this beautiful butterfly some warm day this spring.