Swallowtails vs. Monarchs

Thank you @pattib for posting this beautiful monarch on Unsplash!

This post was originally going to be just about Eastern Tiger Swallowtails, but then I realized that I hadn’t done a versus post in a while, so now it’s Swallowtails vs. Monarchs! This isn’t so much a “which is the better butterfly” post as it is just comparing the two, because in my mind these have always seemed like the most popular lepidopterans.

Meaning these are the only two butterflies whose names I actually know.

Hmm… I may not be that much of an arthropod expert after all; not that I’ve ever claimed to be, my love for animals with exoskeletons greatly exceeds my general knowledge of them. Butterflies have just never been all that exciting to me. I can rattle off a list of ants, but butterflies… eh, these two are all I’ve got. I really don’t have anything against butterflies, I think they’re beautiful and they’re very important to their respective ecosystems, but other insects always piqued my interest a little more. Don’t worry though, butterfly lovers, I’ll definitely be researching other butterfly species for future posts. Now: on to Swallowtails vs. Monarchs!

While both species are in the order Lepidoptera, swallowtails are members of the Papilioninae subfamily and Monarchs belong to Danainae. Like most swallowtail butterflies, Eastern Tiger Swallowtails have a black “tail” on each of their wings. Their wingspan can be up to 5½ inches long, and the wings themselves are typically yellow with black, blue, and orange markings, although some female individuals possess black scales in place of the yellow ones. I actually ran across a massive black Swallowtail in my backyard shortly before I left for school last semester, and she was absolutely gorgeous.

The weathered but stunning swallowtail I spotted in my backyard last year

Monarchs, on the other hand, are smaller than swallowtails with a 4 inch wingspan. Their wings are orange with black, yellow, and white markings, and they lack the tails of their fellow yellow lepidopterans.

While monarchs are famous for their massive migration parties that can consist of thousands of butterflies (and travel thousands of miles when it gets cold out), swallowtails like to keep to themselves. However, male swallowtails sometimes gather around the same puddle to drink water together and bond with their bros in a practice aptly called “puddling.” Why only the males do this, I do not know.

Maybe us introverts should adopt the female swallowtail as our mascot.

Some swallowtail dudes I spotted puddling together over the summer

Both monarchs and swallowtails are flower pollinators, with monarchs enjoying the nectar of milkweed and plants of the Aster genus, among others, and swallowtails preferring flowers like roses, zinnias, and sunflowers. When it comes time to lay their eggs, the Eastern Tiger Swallowtail selects magnolias and rose bushes, while monarch eggs are deposited on their beloved milkweed plants. Monarch eggs resemble teensy pumpkin-lemon hybrids, and swallowtails’ are basically the world’s smallest green grapes. The monarch larvae emerge with elegant black, white, and yellow stripes, but swallowtail caterpillars literally resemble bird poop.

At least it keeps them from getting eaten, and that’s what counts when you’re small and squishy. These caterpillars eventually turn green and resemble snakes (and a certain Pokémon), and can even extend an orange snake-tongue-like protrusion called an osmeterium. The osmeterium not only adds to the snake effect, but can emit an unpleasant odor that wards off predators who get too close.

The chrysalises of both butterflies are also quite different from one another. The monarch’s chrysalis is a light, somewhat-translucent green with little golden knobs at the top… and the swallowtail’s is once again kind of ugly. The swallowtail caterpillar attaches the top and bottom of its abdomen to a branch or trunk of some sort with silk and turns brown and knobby to look like an extension of the plant. I’ll say this for swallowtails – they may not have the prettiest early stages, but they are masters of camouflage.

A swallowtail chrysalis photographed by Judy Gallagher on Flickr
A much prettier monarch chrysalis captured by comforter j on Flickr

The reason monarch larvae can get away with flashy colors rather than hiding from their predators is that they, like their adult counterparts, are kinda toxic. You know that milkweed that the monarchs love so much? It’s poisonous, so when the young caterpillars eat it, they accumulate the poisons in their body. It’s not enough to kill their predators, but it does make them barf. I mean, I don’t know about you, but I’d rather have something spit me out with its partially-digested breakfast than eat me and die from my toxins later when I’m already dead, too.

Yet again showing its skill for mimicry, black swallowtails resemble the Pipevine butterfly, which is also poisonous. Swallowtail predators won’t actually get sick from eating swallowtail butterflies, but if they remember getting sick from a Pipevine, they’ll probably steer clear of its lookalike.

Both swallowtails and monarchs are remarkable butterflies, with monarchs migrating crazy distances each winter and swallowtails fooling other animals left and right with their many disguises. If I had to pick a favorite out of the two, however, I’d definitely have to go with the Eastern Tiger Swallowtail. I still love monarchs, and their larvae are quite adorable. I’ve just had a lot more interactions with swallowtails in my life than monarchs, so they’re a bit more nostalgic to me. That, and monarchs are the most popular butterfly species in my opinion, and I tend to prefer the alternative to the hype. I mean come on, they’re the state insect or butterfly of like, seven states.

…Actually, I just learned that the Eastern Tiger Swallowtail is the state butterfly of six states, including my home state of North Carolina. Huh. Well, if it’s repping NC then it’s gotta be my favorite! That, and swallowtail caterpillars can weave little hammocks for themselves. Can monarch caterpillars do that? No.

Swallowtails win. Case closed.

Another slightly battered butterfly I found over the summer. She had a few nicks in her wings, but she flew up like four stories over a big tree right after I took this picture, so she’s probably fine. I say “she” because the males don’t have blue scales on their wings.

One Comment on “Swallowtails vs. Monarchs

  1. Pingback: Top Ten Arthropod Disguises – The ArthroBlogger

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