On the Wing

Butterfly Hut

Each year, a hundred million North American monarch butterflies complete a timeless ritual: a mass migration from south to north in the spring, and from north to south in the autumn. The journey, up to 3,000 miles in either direction, is too long for any one butterfly to complete in its short lifespan. How, then, do these delicate creatures weighing less than a gram each find their way from the oyamel fir forests of Mexico to as far as Canada and back?

The unseen forces guiding this process remain something of a mystery. How do the monarchs know when it’s time to travel south for the winter? Scientists believe the migration is triggered by multiple cues including the lower angle of sunlight, chemicals from the seasonal decay of surrounding plants, and gently cooling temperatures. Questions about the migration flyway are harder to parse. Are the monarchs guided by the terrain, or do they chemically mark their pathways on the trip north? Do they use photoreceptors in their antennae to navigate with the sun as a compass, or does the species have a genetic memory or “inherited map?” Are they guided by the magnetic pull of the earth? We don’t know for sure.

We do know, however, that the monarchs are in danger. Habitat loss, pesticide use, and an uncertain climate make the migration more difficult each year. Monarch caterpillars depend upon a sole food source, milkweed, for nutrition and shelter, and large-sale decline of milkweed plants is threatening the species. According to the Center for Biological Diversity, the monarch population has declined by 80% in the last 20 years, and the monarchs need help in order to survive.

LS3P’s Savannah office is located along the East Coast flyway, and is an excellent position to offer a safe harbor for at least one step of the journey. As part of a friendly inter-office Earth Day competition held by the firm each April, the office volunteered to design and build a custom “butterfly hut” to provide food and shelter for hatching butterflies, and an opportunity to learn about the monarchs for local students.