Music and NPR News for Central and Northern Michigan
Play Live Radio
Next Up:
0:00
0:00
Available On Air Stations
Local/Regional News

The Decline of the Monarch Butterfly Population

Thousands of monarch butterflies gather in the eucalyptus trees at the Pismo State Beach Monarch Butterfly Grove.
Thousands of monarch butterflies gather in the eucalyptus trees at the Pismo State Beach Monarch Butterfly Grove.

The number of monarch butterflies has declined dramatically since the 1990s.

The first reason is Round Up or glyphosate. The herbicide kills the milkweed plants that are an important part of the monarch’s reproduction cycle.

Second, fewer monarchs are surviving migration to Mexico, possibly because of a parasite and a shortage of nectar to feed on.

Then, monarch eggs need temperatures to be near average. Climate change has meant more volatile temperatures.

Elise Zipkin is a quantitative ecologist at Michigan State University.

“So we found that the size of the population was very highly linked to what those climate conditions were especially in the spring, but also in the summer too.”

Zipkin says planting more native milkweed natural areas can help.