The Morning Cloak Butterfly

In today's post, David Martin talks about the arrival of spring

 with the habits of the Morning Cloak butterfly.

Bird enthusiasts will often claim that spring has finally arrived once certain birds migrate back to Michigan, like the American Robin, the Red-Winged Blackbird, or the Sandhill Crane. However, the emergence of a much smaller winged creature might actually be a better harbinger of warmer weather – the Mourning Cloak butterfly.

The Mourning Cloak butterfly is

the earliest butterfly you can see at Fenner in the springtime.

The Mourning Cloak butterfly (Nymphalis antiopa) is one of the toughest butterflies in Michigan. Unlike many other species of butterflies, the Mourning Cloak butterfly overwinters at Fenner instead of migrating south. It nestles into dense brush, behind loose tree bark, or even under roof shingles to survive the cold winter temperatures. When the daylight hours start to get longer, the Mourning Cloak butterfly will emerge from its hibernation, often when snow still is on the ground. You may even see them at Fenner in late March.

The Mourning Cloak butterfly has large, dark colored wings that soak up sunrays and keep them warm on the chilly spring days. You can see them in sunny areas with their wings outspread and droopily relaxed, trying to warm up their cold wings before flying. This behavior is called “basking”. The bottom sides of its wings are a mottled brown and gray color that helps it blend into its habitat and camouflage it from predators.

Mourning Cloak butterfly basking

on a newly budding branch in early April 2012.

In the early spring, the Mourning Cloak butterfly emerges and begins to look for its springtime meal of tree sap. It likes the same sugar maple sap collected at Fenner during the Maple Syrup Festival. The Mourning Cloak butterfly also likes the sap of many other trees, especially oak tree sap – definitely not the kind you would put on your pancakes! As the sap slows later in the spring and other sources of food emerge, the Mourning Cloak butterfly will get its nutrients from rotting fruit and sometimes flower nectar. Like many types of butterflies, the Mourning Cloak will also land on certain types of damp soil to lick up minerals and even do the same with animal droppings. This behavior is called “puddling”.

Mourning Cloak butterfly puddling

on the gravel portion of a trail at Fenner.

When spring turns to summer and the weather gets hot and dry, the Mourning Cloak butterfly will find a good place to hide away and go into a type of summer hibernation called “aestivation”. As the weather cools in the late summer and autumn, the Mourning Cloak butterfly emerges again to feast on the late summer fruits before finding a place to nestle down for winter. It is not uncommon to see this butterfly in October or early November at Fenner, especially if we have mild and damp fall weather.

The bottom side of the Mourning Cloak butterfly’s 

wings are patterned to provide camouflage to hide it from predators.

In addition to its early spring emergence and late fall hibernation, the Mourning Cloak butterfly tops the record books in a couple other ways. It has a wingspan between 3 to 4 inches, making it one of the larger butterflies you may see at Fenner. For comparison, the Monarch butterfly has a similar wingspan size. The Mourning Cloak butterfly also has one of the longest lifespans of butterflies and can live up to a year. Most will not winter over twice, but they do outlive most of their butterfly counterparts.

This Mourning Cloak butterfly photographed in the early spring 

has tattered wings and probably overwintered at Fenner from the previous autumn.

You can find Mourning Cloak butterflies all over Fenner, but they prefer the more wooded areas because those contain their source of food. Just east of the Woodland Pond along the east side of the Tamarack Trail, there is a low area where it stays damp much of the spring and fall. There are plenty of the Mourning Cloak’s favorite trees in this area and you can almost always find a few of this type of butterfly flitting around or sunning themselves in the spring or fall. Some of them are very friendly and may even land on your clothing if it is a color similar to the tree bark!