Butterflies come in a stunning array of colors and patterns, but some species bear a particularly strong resemblance to one another. The monarch butterfly is one of the most recognizable butterflies, with its vivid orange wings and black veins and white spots. However, there are several other butterfly species that mimic the look of the monarch.
The Viceroy Butterfly
Perhaps the most well-known monarch lookalike is the viceroy butterfly. The viceroy (Limenitis archippus) shares the same vivid orange and black wing coloration as the monarch, and even has very similar wing veining. However, the viceroy can be distinguished from the monarch by the thin, black line that crosses the hind wings. The monarch has no such line.
In addition, the viceroy is smaller than the monarch, with a wingspan of 2.5-3.5 inches compared to the monarch’s 3.5-4 inch wingspan. The viceroy also has a small black line that runs diagonally near the margin of the forewings, which is not present on the monarch.
Mimicry Between Monarchs and Viceroys
The incredibly close resemblance between monarchs and viceroys is an example of mimicry, where one species evolves to resemble another. It’s thought that the viceroy’s appearance mimics the monarch to protect itself from predators. Birds and other animals that prey on insects may avoid the viceroy because the monarch is foul-tasting and poisonous to predators.
By mimicking the monarch’s appearance, the viceroy gains protection while avoiding the biological costs of producing toxins. This mimicry only works, however, if the mimic is far less abundant in the area than the unpalatable model species. If viceroys were more numerous than monarchs, predators would be more likely to chance eating them and learn that they are palatable.
Where Viceroys and Monarchs Live
Monarchs and viceroys broadly overlap across eastern North America, though they aren’t completely sympatric in range. Monarchs are found across the entire continent, from Central America up through Canada. Viceroys occupy a more limited range in the central and eastern United States and southeast Canada.
| Species | Range |
|---|---|
| Monarch | Throughout North America, south to Central America |
| Viceroy | Eastern and central U.S. and southeast Canada |
Within their shared range, monarchs and viceroys often can be spotted flying together and visiting the same flowers. However, viceroys tend to stick to wetter areas near streams, marshes, and swamps, while monarchs are more widespread in both wet and dry areas.
Other Monarch Mimics
In addition to the viceroy, several other butterfly species resemble the monarch. These include:
- Queen (Danaus gilippus)
- Soldier (Danaus eresimus)
- Tiger swallowtail (Papilio glaucus)
- Black swallowtail (Papilio polyxenes)
- Spicebush swallowtail (Papilio troilus)
Of these, the queen is the most similar in coloration and patterning to the monarch. It shares the orange wings with black veins. However, the queen also has a wide black border on its wings, lacks the white spots that monarchs have, and has an overall more angular and elongated wing shape.
The soldier butterfly is also a close match, though it lacks some of the black wing venation of true monarchs. It also has more irregular white spotting on its wings. Like the viceroy, swallowtails have the orange and black coloring but can be distinguished by their distinctive tails on their hindwings.
Why So Many Monarch Mimics?
Many theories have been proposed for why so many different butterfly species have evolved a similar look to the monarch. Most center around the concept of Müllerian mimicry. Under Müllerian mimicry, multiple unpalatable species evolve to have warning colors, benefitting both mimics and models. Some possible explanations for monarch-like mimics include:
- Monarchs and their mimics may actually all be somewhat unpalatable, reinforcing avoidance by predators
- Mimics dilute the effect of any single model species, requiring predators to learn multiple patterns
- Mimics strengthen the warning signal by dominating the color pattern in an area
Whichever explanation is correct, the benefit to multiple species from sharing bright orange coloration seems to have led to a proliferation of monarch-mimicking butterflies across the Americas.
The Importance of Flower Color
Another likely factor favoring monarch-like coloration is flower color preferences. Many of the flowers frequented by butterflies tend to be pink, purple, orange, or red. Bright orange wings may stand out against such backgrounds, helping the butterflies spot promising nectar sources.
Orange is also highly visible to insects but not as easy for birds to spot against green foliage. So flower color preference and camouflage against predators may have additionally selected for repeated orange mimicry among American butterflies.
| Butterfly Species | Wing Color |
|---|---|
| Monarch | Vivid orange |
| Viceroy | Orange |
| Queen | Orange |
| Soldier | Orange |
| Tiger swallowtail | Orange and black |
Conclusion
While the monarch butterfly has one of the most recognizable color patterns in the insect world, it is far from alone in sporting vivid orange wings. Many mimics, especially the viceroy butterfly, share the colorful patterning of monarchs. This phenomenon has many possible evolutionary origins, but seems to benefit both the model monarchs and their copycat species, allowing them to avoid predators, attract mates, and efficiently locate flowers.
So next time you spot a monarch-like butterfly, look closely – it may just be an imposter relying on the monarchs’ resemblance for its own survival!