Why do viceroy butterflies copy monarch butterflies?

The world of butterflies is full of marvels and puzzles, and one of the most fascinating phenomenon is mimicry. Some of the most famous examples include Viceroy butterflies copying monarch butterflies. In this post, we will investigate the reasons behind this mesmerizing imitation and understand the secrets behind this impersonation.

Viceroy butterflies (Limenitis archippus) are North American butterflies which bear remarkable resemblances to monarch butterflies (Danaus plexippus). The two species share bright orange wings with black veins, rendering them practically undetectable to hunters. So then, why have the viceroyal butterflies staged this similarity?

1-Protection from predators

Monarch butterflies are notorious for their toxicity, developed as caterpillars by their feeding on poisonous plants. They produce chemicals in their bodies that make predators sick or kill them. Viceroy butterflies, by emulating the looks of monarchs, benefits from this protection. As a result, predators, having already fallen victim to the toxicity of monarchs, refrain instinctively from the viceroyal butterflies, assuming that they are also toxic.

2-Survival advantage

The pattern of similarity of viceroyal butterflies gives them a survival advantage. By closely resembling monarch butterflies, they benefit from the monarchs' reputation for toxicity without having to develop their own defense mechanisms. This increases their chances of survival by avoiding being preyed upon by hungry predators.

3-Learning by association

Predators have the ability to learn by experience. When a predator tries to capture a monarch butterfly and experiences the effects of its toxicity, it associates the appearance of the butterfly with danger. When it then encounters a viceroy butterfly, which closely resembles it, it instinctively avoids attacking it, thus avoiding an unpleasant experience.

4-Co-evolution between monarch butterflies and viceroy butterflies

The close resemblance between viceroy butterflies and monarchs is an example of co-evolution. Over time, viceroyal butterflies have evolved this imitation to survive in environments where monarchs are abundant. Genetic variations that promote more accurate imitation have been selected for, leading to an increasing resemblance between the two species.

Finally, the mimicry of viceroyal butterflies toward monarch butterflies is a remarkable survival strategy.