The Monarch Butterfly’s Story

The Monarch Butterfly’s Story
Scientists are studying mimicry in many insects and other animals. They are studying bumblebees, plant-sucking bugs, poison dart frogs, sea slugs, sea cucumbers, and flatworms, as well as other butterflies and moths. In recent years, scientists found that one of the most common examples of a Batesian model and mimic was wrong. This pair consists of the monarch butterfl y and the viceroy butterfly.


The monarch is a beautiful orange, black, and white butterfly of North, South, and Central America. It feeds on poisonous milkweed plants as a caterpillar. It is unharmed by the poison and stores it up in its body to make itself poisonous to predators. This protection lasts into adulthood. Birds that grab monarchs quickly drop them, or throw them up if they have already swallowed them. Studies show that such birds refuse to eat monarchs or their look-alikes again.

One of the monarch’s look-alikes is the viceroy butterfly. For more than 100 years, the viceroy was thought to be a Batesian mimic of the monarch: tasty, but avoided by birds because of how it looked. In 1991, scientists put an idea to the test. They removed the wings from dead butterflies, including some monarchs and viceroys, then fed the bodies to red-winged blackbirds. The experiment showed that the birds found the viceroys just as nasty-tasting as the monarchs.

The viceroy and the monarch are now thought to be part of a group of Müllerian mimics that includes the monarch’s relatives, the soldier butterfly and the queen butterfly.