When I was growing up, we used to see Viceroy butterflies fairly often. The ones in that area tended to be noticeably smaller than the local Monarchs; they also don’t look the same in flight. Where I butterfly watch now, in the areas around and west of Toronto I don’t often encounter Viceroys: and the Monarchs here come in a greater variety of sizes from quite small to majestically large. (The ROM Field Guide to the Butterflies of Ontario says they can be from 93-105 mm, 3.7-4.1 inches.) Still, when I spotted an orange and black butterfly at the Wainfleet Quarry near Lake Erie this summer, I hurried closer because I was confident it was a Viceroy.
What Marking Makes It Easy to Tell a Viceroy from a Monarch?
Luckily for butterfly watchers, there is a clear obvious difference in the colouring of Monarchs and Viceroys. The Viceroy has a black line making a U shape about 1/3 of the way up from the bottom edge of the hindwings. Monarchs don’t have this “smile.”
Viceroys are also noticeably smaller: the ROM guide says 53-81 mm.
Do Viceroys Migrate South for the Winter?
Nope. Or at least that’s not what’s reported so far. The ROM guide says that they over-winter as caterpillars.
Are Viceroys Distasteful or Poisonous to Some Predators Like Monarchs?
Monarchs usually contain chemicals they collected as caterpillars while eating milkweed that make them unpleasant for some birds and animals to eat and make them actually poisonous to others.
Many people assumed that Viceroys were just copying Monarchs colouring for protection by tricking predators. Viceroy caterpillars usually feed on willows and poplars, not milkweed.
According to the ROM guide, however, it turns out that Viceroys themselves are distasteful to predators. From what I can see on various non-scientific websites, it is the salicylic acid from eating Willow leaves that makes some Viceroys distasteful. If I find a more reliable source of info in the future, I’ll update this article.
Whether they taste good or not, I was glad to get a chance to see a Viceroy up close again. I hope the next time I visit the Quarry I’ll find one of its descendents.
- An October Ontario Back Yard Full of Butterflies
- The Butterflies of the End of Summer in Mississauga
- Giant Swallowtails Invade Ontario
- How to Sex a Monarch
Do you have both Viceroys and Monarchs visiting your flowers? Please share your sightings with a comment.