Rocky Mountain parnassian facts for kids

Quick facts for kids Rocky Mountain parnassian
In the Cascade Range, British Columbia
Scientific classification

The Rocky Mountain Parnassian (scientific name: Parnassius smintheus), also called the Rocky Mountain Apollo, is a beautiful butterfly that lives high up in the Rocky Mountains. You can find it in both the United States and Canada. This butterfly is part of the swallowtail family and is known for its white to light yellow-brown wings. It has special red and black markings that tell predators, "Don't eat me! I taste bad!"

When they are young (larvae), these butterflies mostly eat the leaves of a plant called Sedum lanceolatum. As adult butterflies, they drink nectar from the same plant. They love sunny meadows and try to stay away from forests because they need lots of light. Male butterflies fly around a lot, looking for food and female butterflies. Females, however, prefer to fly less. Males often come out of their cocoons earlier than females. They look for new female butterflies that haven't flown much yet.

Even though this butterfly is not yet endangered, its homes are shrinking. This is happening because of climate change and human activities over the past few decades. Scientists are working to protect these amazing creatures.

Where Do Rocky Mountain Parnassians Live?

A beautiful meadow habitat at Mitchell Point

These butterflies live mainly in the Rocky Mountains. This huge mountain range stretches across Canada and the United States. In Canada, you can find them in places like Yukon, Alaska, and British Columbia. In the U.S., they live as far south as New Mexico.

You'll often spot P. smintheus in sunny alpine and subalpine meadows. Male butterflies especially like meadows with lots of nectar flowers and their favorite food plant, Sedum lanceolatum. They also prefer meadows where more female butterflies are present. Males might even visit several meadows to find the best one. This is probably because flying around so much uses a lot of energy, so they need good food sources. Female butterflies don't seem to be as picky about the meadows they choose.

What Do Rocky Mountain Parnassians Eat?

The main food plant for young butterflies: Sedum lanceolatum

The main plant that young P. smintheus butterflies (larvae) eat is called Sedum lanceolatum, or spearleaf stonecrop. This plant has yellow flowers and grows well in rocky areas across Western North America. Sometimes, the larvae might eat other types of stonecrop plants too. These food plants usually grow on steep, gravelly slopes, often above the tree-line.

S. lanceolatum has a special chemical called sarmentosin that keeps most plant-eating animals away. This is good news for the butterfly larvae because it means their food plant is usually safe! The larvae also take this sarmentosin into their own bodies. This makes them taste bad to predators, giving them a natural defense.

However, if the S. lanceolatum plant gets damaged, the larvae eating it might not grow as well. This could be because the plant tries to defend itself. So, the larvae often eat quickly and then move to another plant. They usually feed on a plant for less than half an hour.

There's an interesting fact about their food plant: from November to February, the leaves are actually poisonous to the larvae! But for the rest of the year, the larvae can eat and grow normally. If the snow melts too early, before March, the eggs might hatch when the plant is still toxic, and the young larvae won't survive.

How Rocky Mountain Parnassians Reproduce

Finding a Partner

Male P. smintheus butterflies sometimes have trouble seeing clearly. They will investigate almost any flying or sitting object that looks like a female butterfly in size and color. They often look for light-colored objects. Males usually emerge from their pupae earlier than females. This gives them time to fly over a large area, searching for newly emerged females. They fly long distances, only stopping to warm up in the sun or to eat.

Choosing a Partner

Males prefer to mate with young females, especially those that haven't flown much yet. Female butterflies only mate once and lay eggs once. The youngest females have the most potential to lay many healthy eggs. This is why males choose them. Females also seem to release a special scent (pheromone) when they are young, which fades over time. A female butterfly has a short window, about three days, to find a mate. Not all females find a mate; about 14% might not.

Mating Behavior

A special "seal" on a female butterfly's abdomen after mating

When a male finds a female, he will try to mate with her. If she hasn't mated before, they will usually succeed. After mating, the male places a small, waxy "seal" on the tip of the female's abdomen. This is called a mating plug. This special seal helps to make sure that the first male's genes are passed on and prevents the female from mating with other males. Sometimes, this seal isn't placed perfectly. If a female doesn't want to mate, she might close her wings tightly to try and hide from the male.

Special Gifts from Males

The waxy seal that the male places on the female's abdomen is like a special package. Its main job is to stop the female from mating again. This helps the male ensure that his offspring will be the ones she carries. Scientists have found that this seal doesn't really change how many eggs the female lays. This means its most important role is to prevent multiple matings.

Laying Eggs (Oviposition)

Female butterflies lay their eggs near the Sedum lanceolatum plant, but usually not directly on it. They look for good meadows that have this plant, even if there aren't a huge number of them. Females will travel further to find the right meadows before laying their eggs. Scientists think there might be a special smell or signal from the plant that tells the females where to lay eggs. It's not fully understood why they don't lay eggs directly on the plant, but one idea is that it helps protect the eggs from predators that might be on the plant.

The Life Cycle of the Rocky Mountain Parnassian

Egg Stage

The eggs are white and round, but a bit flat on the top and bottom. They have a bumpy surface. The part where the egg was fertilized is brown and slightly sunken. The eggshell is quite thick, which helps protect the egg from predators, tiny parasitoids, and bad weather during the winter. A female butterfly usually lays about 75 eggs. Interestingly, the young larvae don't eat their eggshells after hatching, even though they contain nutrients.

Eggs are often laid on the underside of flower heads, leaves, sticks, stones, moss, or even clumps of dirt. Sometimes, they are laid on the food plant itself, but often they are laid more than a meter away. The tiny butterfly embryo develops inside the egg within a month. However, the egg doesn't hatch until the snow melts the following spring.

Larva Stage (Caterpillar)

A Rocky Mountain Apollo caterpillar eating lanceleaf stonecrop in Waterton Lakes National Park, Alberta

The larva, or caterpillar, goes through five growth stages (called instars) before it turns into a pupa. This takes about 10 to 12 weeks. The first stage larva is black with many hairs and a dull black head. As the caterpillar eats the S. lanceolatum plant, it stores the sarmentosin chemical in its body. This makes the caterpillar taste bad to predators.

After the second growth stage, bright yellow markings appear on its body. These markings act as a warning sign to predators, showing that the caterpillar has even more of the bad-tasting sarmentosin. The fifth stage caterpillar is black with many short, fine black hairs. It has two rows of bright yellow spots on its sides and two on its back. It also has tiny, pale yellow organs behind its head called osmeteria, which look a bit like feelers.

Since caterpillars might not hatch right next to their food plant, they have a quick way of searching for it. They usually eat their fill quickly, then move to a sunny spot on the ground to warm up. If something disturbs them, they twitch violently and drop to the ground to hide. They might also release a bad-smelling brown liquid.

Pupa Stage

The pupae are dark yellow-brown to red-brown. They form in leaf litter, gravel, or rocks near the soil surface. The larvae don't spin a full cocoon. Instead, they gather a little silk around themselves to attach to their surroundings. When the new butterfly is ready to emerge, it has two tiny hooks to help it get out of its pupal case.

Adult Stage

An adult Rocky Mountain Parnassian butterfly

Adult butterflies are usually a translucent yellowish-white with black, grey, and red markings. Their colors can vary a lot! Their wingspan is typically between 2 and 3 inches (5 to 7.5 cm). The top of their front wings has a grey band along the edge and a faint grey band further in. The edges of the wings often have small black triangles at each vein.

Both male and female butterflies usually have bright red spots on their back and front wings. Butterflies living at higher elevations often have darker females. Both sexes tend to be smaller at lower elevations. Adult butterflies mostly drink nectar from yellow-flowered plants like Potentilla fruticosa, Solidago multiradiata, Senecio canus, and S. lanceolatum.

How Butterflies Move Around

Butterflies move between different meadows more easily when the meadows are connected. More butterflies tend to move into larger groups, and fewer leave large groups. This might be because males are actively searching for young females.

These butterflies usually avoid the edges of forests. They also fly less often and slower in forests compared to meadows because there's less light. They travel much further in meadows than in forests. Since they avoid forest edges, meadows surrounded by forests will have fewer butterflies moving in and out.

Who Are Their Predators?

Rocky Mountain Parnassians face dangers at every stage of their lives. Their eggs can be eaten by plant-eating mammalians if they munch on the host plant. For example, on Dividend Mountain in British Columbia, cattle grazing after the eggs are laid can reduce the butterfly population.

Birds are major predators of both caterpillars and adult butterflies. Small mammals like mice, chipmunks, and squirrels also hunt them. Chipmunks might carry butterflies back to their dens, then remove their wings to eat the body. Orb-weaver spiders and other insects also prey on adult butterflies. Even ants can be "partial predators," cutting off parts of the wings for food while the butterflies are resting.

How They Protect Themselves

Caterpillars store sarmentosin from their food plant to protect themselves from predators. An adult butterfly can have a good amount of this chemical in its body. The concentration of sarmentosin is highest in the butterfly's wings. This is helpful because the wings are often the first part a predator touches.

Because of this chemical, the butterflies have a strong smell. If attacked, they might release a brown fluid from their rear that also smells bad. This fluid can even irritate human noses! Scientists believe sarmentosin is a very bitter compound, which makes predators less likely to try eating them again. Their white wings with black and red markings act as a visual warning to birds that they taste bad. Their strong odor warns rodents. Interestingly, male butterflies might have more of these bad-tasting compounds than females, as chipmunks tend to eat more females.

How They Fly

These butterflies fly from early June in lower areas until late September in high alpine tundra. They are univoltine, meaning they have only one group of offspring each year. Male butterflies are usually seen more often than females. Females generally try to avoid flying, preferring to crawl when looking for places to lay eggs. Males, however, fly much more readily.

Even though males fly more, both sexes travel similar distances overall. Most of their movement happens in open, non-forested areas, and they don't often cross valleys. They fly most frequently about 20 meters into meadows and least often 20 meters into forests. Their willingness to fly depends on how bright the light is.

Protecting the Rocky Mountain Parnassian

Right now, the P. smintheus butterfly is common in the Rocky Mountains. However, some related species in Europe, like Parnassius apollo and Parnassius mnemosyne, are in danger because they are losing their homes and their populations are becoming isolated. These same problems are starting to affect P. smintheus too.

Over the past few decades, due to things like fire prevention and possibly global warming, the tree line has moved higher up the mountains. This has caused meadow areas to shrink by over 78% since 1952. If the tree line keeps rising, there will be fewer feeding grounds for the butterfly larvae, as they prefer to eat further away from the trees.

To help these butterflies, we need to protect their remaining habitats and make sure different populations can still connect with each other. This can be done by preventing forests from growing into meadows and by keeping open, unforested paths between different meadow patches.

Parnassius smintheus is also sensitive to changes in temperature from climate change. For example, warm Novembers or extreme cold and warm temperatures in November are linked to big drops in their population. If it gets warm too early in November, the eggs might hatch before winter is truly over. Then, when normal cold temperatures return, the young larvae would die.

Different Types of Rocky Mountain Parnassians

P. smintheus and P. clodius from a butterfly book published in 1898

The P. smintheus butterfly has several different subspecies, which are like slightly different versions of the same species. Here are some of them:

• P. s. behrii W. H. Edwards, 1870 found in the Sierra Nevada mountains
• P. s. magnus Wright, 1905 found in Washington state
• P. s. maximus Bryk & Eisner, 1937 found in the Rocky Mountains
• P. s. olympianna Burdick, 1941 found in the Olympic Mountains and Vancouver Island
• P. s. pseudorotgeri Eisner, 1966 found in Colorado (San Juan Mountains)
• P. s. sayii Edwards, 1863
• P. s. smintheus Doubleday, 1847
• P. s. sternitzkyi McDunnough, 1936 found in North California (named after Robert F. Sternitzky)
• P. s. yukonensis Eisner, 1969 found in South Yukon and British Columbia

(You might also hear about P. s. xanthus Ehrmann, 1918: from Washington State)

Butterflies That Look Similar

The P. smintheus butterfly is sometimes confused with Parnassius phoebus, which is a closely related species found across the northern parts of the world. Some scientists even group the North American populations of these butterflies into two or three different species. Usually, the butterflies found furthest north are considered P. phoebus, while the others are P. smintheus. The best way to tell them apart is often by where they are found.

Here are some other butterflies that look similar:

• P. phoebus (Phoebus Apollo)
• P. clodius (Clodius Parnassian)
• P. eversmanni (Eversmann's Parnassian)