Species Spotlight: Monarch Butterfly

monarch butterfly on a flower

Questions and Answers

Why is the declining availability of milkweed a threat to monarch butterflies?
Their dependence on milkweed alone as a host plant, and declining milkweed abundance throughout the monarch range, is threatening monarchs.

What adaptation protects monarch butterflies?
The bright orange and black colors of the monarch warn predators that they are inedible, due to their diet of toxic milkweed. Few animals can eat monarchs without getting sick. Other nontoxic butterfly species, such as the viceroy butterfly, take advantage of the monarch’s defenses and have evolved to look exactly like them to fool predators. This phenomenon of nature is called mimicry.

How do monarch butterflies sense when it is time to migrate?
Monarchs know when it’s time to migrate south for the winter based on signals from the environment indicating the seasons are changing. When it’s time, the butterflies will lift up on air currents high into the sky and embark on their journey.


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