NewsLocal News


Monarch butterfly population declining

Global warming and climate change the cause
Posted at 8:50 AM, Jul 28, 2021

(WXMI) — We all see them! Most of us love their beauty and recognize them instantly: the Eastern Monarch Butterfly.

Their migration is incredible every year from Mexico into the Midwest, Great Lakes and Canada, but their population is decreasing. Most of these butterflies live only a month or two, but the later generations can live as long as eight months or so.

Their food source is milkweed. But due to herbicide applications, that has decreased. Researchers also say global climate change and warming is the real culprit as to why these monarchs are in decline. Hotter, drier periods are not conducive to the monarch. They like cooler, wetter periods in the summer breeding grounds of the Midwest, Great Lakes, and southern Canada. Climate change has warmed these areas over the years despite the fact that precipitation has slightly and may be producing more milkweed.

Researchers believe there may be as much as an 80% decline in these monarchs, primarily from the mid-1990s through about 2004.

It's very difficult to actually "quantify" the lesser population and to what extent they have declined, but researchers in the biology department at Michigan State University say it has taken a host of volunteers around the country to examine the population.

How these butterflies are spread out over the land from one year to the next is how they believe the population is in decline. They are simply seeing less of them.

Temperatures have warmed and these insects are not partial to warmer/hotter temperatures. That said, continued climate change and warming will likely diminish the monarch population, but at this time we are not looking at an extinction of the species, but it will need to be monitored. Forecast models will need to be watched since they show a continuation of a declining population.

Many thanks to the biology department at Michigan State University for contributing to this story. Make sure to watch the attached video for the complete story.