News, Culture and NPR for Central & Northern Michigan
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations
91.7FM Alpena and WCML-TV Channel 6 Alpena have been restored. Click here to learn more.

The Decline of the Monarch Butterfly Population

Thousands of monarch butterflies gather in the eucalyptus trees at the Pismo State Beach Monarch Butterfly Grove.
George Rose
/
Getty Images
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.

Lester Graham reports for The Environment Report. He has reported on public policy, politics, and issues regarding race and gender inequity. He was previously with The Environment Report at Michigan Public from 1998-2010.