Mourning Cloak Butterfly – Species Profile & Facts
The Mourning Cloak butterfly (Nymphalis antiopa) species is known by many names, including white petticoat, grand surprise, and Camberwell beauty. It is one of the most exhilarating butterfly species that ranks as protected in some areas of the Globe and a pest in others.
We will ignore these aspects for now and focus on the Mourning Cloak’s most defining traits to create this species’ complete profile. Let’s see what this butterfly species has for us.
How to Recognize a Mourning Cloak Butterfly?
The Mourning Cloak is a fascinating Lepidoptera for a variety of reasons, including its appearance. This species may not look like much at first glance, until you understand the mechanism behind its ingenuous dressing. The butterfly displays a chocolate-brown, fluffy body, covered in thin and soft hairs, especially around the head and thorax. The abdomen is long and silky, longer than the butterfly’s thorax and head combined.
But it’s the wings where all the magic happens. The butterfly’s wings are maroon, a mix of brown and red with rusty shades. The wings’ margins display blue dots, under which there are thick, yellow bands covering the wings’ full length. This is how the wing looks from a dorsal perspective.
From a central vantage point, the view is completely different. The ventral side of the butterfly’s wings looks like genuine charcoal wood. Think of burnt charcoal with cracks, discolorations, and tainted by ash. The marginal bands are now white and display the same carbonized look, rendering the butterfly practically invisible while motionless.
Another key note here is that it’s almost impossible to tell the difference between males and females. The Mourning Cloak is almost genderless to an untrained eye, creating confusion among would-be butterfly breeders. Both genders display similar coloring with only minor variations that are generally inconsistent and irrelevant.
The easiest way to differentiate between the genders is to monitor the butterfly’s behavior. The male Mourning Cloak is territorial and will patrol the same area to increase its chances of mating and get fast access to the best resources. On the other hand, females don’t linger in the same area for too long.
They will fly to search for food and will change location pretty often.
Another useful sign may be to assess the size of the abdomen. The female tends to grow a bulgier abdomen, especially when it’s time to lay eggs.
What Does Mourning Cloak Butterfly Caterpillar Looks Like?
This species’ caterpillar is among the most unusual larvae since it displays features similar to the adult butterfly. In fact, the Mourning Cloak caterpillar is probably the only one in the Lepidoptera family that resembles its adult form.
The caterpillar is usually around 2 inches when nearing its 5th instar, which is around half of the butterfly’s total wingspan. It has a long and slim body, covered with tiny hairs and long, black, and ominous spikes.
The caterpillar will display a similar coloring to the adult butterfly, contrasting dark brown and rusty-red nuances. They have segmented bodies, each segment containing a large red spot in the middle with one black spike coming out.
They also have tiny, bright red legs that stand out under their ominous-looking, black bodies. As another interesting aspect, Mourning Cloak caterpillars are gregarious in nature. It’s not uncommon to spot large gatherings of several dozen caterpillars in one place, forming one compact mass.
They will also react in unison when sensing a threat and will all raise their heads and begin bobbing. Fun sight.
How Big Does Mourning Cloak Butterfly Get?
The adult butterfly will reach varying sizes, between 3 to 4 inches. These are the maximum values since most species will fall slightly shorter.
Where do Mourning Cloak Butterflies Live?
The Morning Cloak is spread all over the world, more notably throughout Eurasia and America. The butterfly prefers wooded areas, preferably with temperate or even cold temperatures. As a hibernating species, the Mourning Cloak doesn’t mind temperatures as low as -31 F, which makes it unique in the Lepidoptera family.
What do Mourning Cloak Butterflies Eat?
The adult butterfly is a rare species that doesn’t consume flower nectar. The Mourning Cloak butterfly prefers tree sap and rotting fruits as primary food options. This explains the butterfly’s specialized coloring and pattern.
The adult Mourning Cloak spends most of its life on tree bark in wooded areas, so its camouflage evolved to provide maximum protection. The butterfly’s specialized diet also minimizes its role as a pollinator since males don’t consume nectar at all.
Some females do, however. Reports exist of Mourning Cloak females visiting various flowers to pick up some nectar, but this happens very rarely.
What Plants Attract Mourning Cloak Butterflies?
None. The Mourning Cloak isn’t fond of plants, unlike most species of Lepidoptera. Both the caterpillar and the adult butterfly prefer to linger around trees for food, protection and resting. The caterpillar has a sweet tooth for trees in the deciduous category.
Deciduous trees rank as giant plants and are, basically, trees that shed their leaves in fall. They also produce fruits that fall to the ground when ripe and shed flower petals following pollination or when their time is up. The term deciduous isn’t even specific to the plant world.
It literally translates by ‘falling off when mature,’ which can describe a lot of things in nature. As a result, we have deciduous teeth (baby teeth in mammals that fall after a certain age), deciduous antlers in stags, etc.
The most common deciduous trees include oak, maple, walnuts, birch, aspen, elm, beech, and many others. Some shrubs fall into the same category, like grapes, wisteria, poison ivy, etc., but these are irrelevant to the topic at hand.
The Mourning Cloak caterpillars will prioritize these trees to provide them with the necessary nutrients throughout their developmental phase. Other preferred plants include hackberry, wild rose, poplar, or willow. Adults use the same trees as food, sucking on tree sap and consuming ripe and rotten fruits whenever possible.
How do Mourning Cloak Butterflies Reproduce?
The mating system depends heavily on the male’s behavior. The Mourning Cloak butterfly male is known to display lekking behavior. This is typical to various other animals and consists of a form of male-based competition. The males gather in one area and compete against each other to impress the females, which will typically settle for the winner.
The butterflies don’t usually fight among each other. Their lekking behavior refers to them establishing given territories and defending them against competitors and intruders. Mourning Cloak males prefer to patrol a set territory, scanning for females in carefully chosen locations. These include all areas where Mourning Cloak females like to visit, like ponds, river streams, gardens, etc.
After spotting the female and making his intentions clear, the male will pass on the sperm, marking the beginning of the reproductive process.
After that, the butterfly’s life cycle enters the 4 developmental phases, but with some interesting twists:
- Egg – The female lays the eggs on the host plants in bulks. The eggs are generally pale, displaying varying colors like olive-green and amber yellow. They will change color during the developmental phase, becoming nearly completely black as the hatching approaches and the fully-formed butterfly is ready to emerge.
- Larva – The Mourning Cloak larvae spend their entire lifespan on the host plants serving as food and shelter. Its alarming coloring will keep predators away in most cases, ensuring the larvae’s survival at higher rates than other species. Typically, the Mourning Cloak larvae are pretty shy and sedentary creatures that won’t move too much so long as they have sufficient food and shelter. They will often form larger quasi-social groups, protecting each other from predators, a behavior which is also seen in the adult butterfly. The larva undergoes the traditional 5 phases of molting, growing larger each time, up to a maximum of 2 inches. One noticeable sign that the larva prepares for pupation is its higher levels of energy, causing the caterpillar to change locations more frequently.
- Pupa – The Mourning Cloak pupa looks like something coming from an alien horror movie. It is generally light brown, green, or grayish, with an elongated look and 2 sets of sharp spines covering its upper portion. It will measure no more than 1.2 inches.
- Adult – The adult Mourning Cloak butterfly will emerge in late summer, 7 to 18 days after the pupation phase has started. Most butterflies will spend some of the winter buried in tree bark or rotten wood in a hibernating state throughout the cold season. They will reactivate during spring when they seek a compatible mate to begin the reproduction process.
Where do Mourning Cloak Butterflies Lay Their Eggs?
The Mourning Cloak female will look for larvae-oriented host trees like elm, birch, willow, hackberry, oak, and others. These will provide the future larvae with shelter against predators and ensure a rich source of nutrients.
Are Mourning Cloak Butterflies Rare?
Not only are they not rare, but they actually rank among the most widespread species on butterflies available. This is mostly due to the butterfly’s ability to overwinter and hibernate in conditions that kill any other Lepidoptera species.
It’s not quite uncommon for many butterfly species to hibernate, but that usually only happens as pupae. The larva will pupate when the cold season approaches, preferably in a hidden and safe area, and remain there throughout the cold season. It’s almost unheard of to have adult butterflies hibernating, which means that the Mourning Cloak is the exception.
The adult butterfly will bury itself in tree bark to find shelter from the elements and remain there, in a vegetative state, until the winter is over. There’s a famous story about one researcher breeding and investigating this species to understand its overwintering behavior and adaptability.
He kept several Mourning Cloak butterflies in its fridge several months throughout the winter and took them out when spring came. The butterflies came back to life and appeared normal and healthy, mating soon after.
This impressive adaptability allowed the Mourning Cloak to thrive in conditions that would kill any other species of Lepidoptera.
Is the Mourning Cloak Butterfly Endangered?
No, this species isn’t ranked on the endangered list. It is currently thriving in many parts of the Globe, in areas where human interference is minimal. This protects the species against human-related population decline that affects so many other butterfly species.
How Long do Mourning Cloak Butterflies Live?
This species is listed as having the longest lifespan of all Lepidopterans. This isn’t due to the butterfly’s overall lifespan, which can reach a year, combining all of its metamorphosis phases. Other butterfly species can also reach a similar lifespan if we consider that they overwinter as pupae.
However, in those cases, the adult butterfly will only live around 2 weeks since it’s the pupa that hibernates.
When it comes to Mourning Cloak, the adult butterfly hibernates, not the pupa. This means that this species qualifies for the longest-lifespan in adult form.
What is the Meaning of Mourning Cloak?
The butterfly’s name is imbued with meaning, referencing 2 interesting aspects via its common and Latin name:
- Mourning Cloak – This name references the mourning clothes that women would wear during Victorian England. They resembled the butterfly’s pattern, except the clothes were black rather than brown or any other similar variation.
- Nymphalis antiopa – A combination of 2 different concepts, equally interesting and fitting. Nymphalis reminds of the Greek nymphs, legendary, beautiful women who would only appear to travelers in wooded areas. Reminds you of someone you know? Antiopa comes from Antiope, the daughter of Ares, the famous and infamous God of war. She was also the queen of the Amazons, the most feared female fighters in Greek legends.
Is the Mourning Cloak Butterfly Poisonous?
No, but some species of Mourning Cloak caterpillars can produce an irritating effect via their dorsal spines. The fact that this species has no chemical defense mechanisms explains why it has so many predators. These include bugs, ants, wasps, mites, and beetles eating the butterfly’s eggs and even larvae, praying mantids, dragonflies, mammals, reptiles, and birds that prey upon the adult butterfly.
Furthermore, this species’ larvae will also consume the unhatched eggs around them to add salt to the wound.
To overcome its lack of chemical defenses, the Mourning Cloak butterfly had to develop other defense mechanisms, which include:
- Thanatosis – This term defines the play-dead behavior that Mourning Cloak uses at times. The butterfly will fold its wings and legs and remain motionless for several minutes upon sensing a threat. It will return to normal once it senses no danger.
- Color-based camouflage – The adult butterfly can achieve impressive camouflage, allowing it to blend within its environment almost perfectly. The adult butterfly resting on a tree bark with its wings folded is near invisible. Predators usually only have a chance at detecting the butterfly when it moves or in mid-flight.
- Grouping behavior – This is atypical behavior to the Lepidoptera world. The grouping aspect is specific to the caterpillars, which are gregarious in nature and will often form compact groups. When a threat is nearby, the caterpillars will all raise their heads and weave back and forth or from side to side. It almost appears as a choreographed motion, creating the impression of one larger organism, which can scare away any potential predators.
- Swarming behavior – Adult butterflies can adopt a form of swarming behavior when encountering predator birds or even other butterflies. They will form a group and charge the perceived threat head-on to intimidate and scare the predator away. And it often works.
These evolutionary behaviors allow the Mourning Cloak to achieve quite an impressive survival rate compared to other Lepidoptera species.
The Mourning Cloak is an astounding butterfly species, characterized by several unique traits:
It has the longest lifespan, as the adult can hibernate for months in inhospitable conditions
The males display polygynous behavior (can mate multiple times with different females during one season)
They have impressive defensive mechanisms to protect themselves from predators
The males and females are virtually indistinguishable by color or patterns, which is atypical for the Lepidoptera family, and so much more
We really appreciate the comprehensive effort you have made Richard. You answered every question we had and then some !
Thank you for sharing your knowledge.