How to help endangered monarch butterflies

Many people admire migratory monarch butterflies for their beauty and their annual journey across the Americas, but the beloved orange-winged creatures have recently found themselves on the Red List of Threatened Species.

Biology professor Allen Hurlbert researches the impact of climate change on biodiversity and the geographic patterns of birds and insects, including butterflies like the monarch. He started Caterpillars Count!, a citizen science project that measures the seasonal variation of arthropods like caterpillars on trees and shrub foliage.

Hurlbert said monarchs differ from most butterflies due to their migratory nature. He attributes the monarch’s decline to several factors.

Deforestation can impact the monarch population. Hurlbert said the butterflies are also vulnerable because their caterpillars and larvae are specialists, meaning they can only feed and grow on milkweed plants, while many other butterflies are generalists and feed on different types of leaves.

Hurlbert said small, localized and short-duration weather events, like an intense storm or an ill-timed cold front or heat wave, could potentially take out a large percentage of the monarch population if it happened where many butterflies were gathered.

“The silver lining is the attention being drawn to these declines,” he said.

Members of the public can aid the monarch population by growing milkweed, avoiding the use of pesticides and participating in community caterpillar monitoring and reporting.