Simply Science: Monarch Butterflies

MINNEAPOLIS -- Most Minnesotan's recognize the striking orange and black wings that characterize a Monarch Butterfly.

But our favorite flyers are struggling this year.

"The fact that there was drought this year but also last year was a double whammy for a lot of populations of organisms," says Dr.Emilie Snell-Rood, an Associate Professor at the University of Minnesota's department of Ecology, Evolution and Behavior.

That double whammy of drought, plus an early spring was not good news for Monarchs. It meant there was less high quality milkweed available for the Monarch caterpillars.

Snell Rood says, "For a lot of plants, they are actually more nutritious when they're younger. They have higher nitrogen and more protein in the leaves when the plants are younger. So if the plants are way ahead when the butterflies get here later, then there might be some sort of disconnect. The butterflies might not be eating the most nutritious plants."

That's on top of habitat loss, pesticides and natural killers like fungus and parasites.

She says it's not time to panic but it is time to pay attention. "The population of most organisms will fluctuate sometimes quite a bit from year to year, so it's the long term trends that matter. We don't want it to get below some critical thresholds because then there are inbreeding problems and things like that. I think it's important to have some concern, but not necessarily panic over the decline in population."

Final numbers won't be in until the end of the season, but Snell-Rood says the decline is significant.

Fun fact: Monarchs travel all the way down to Mexico and through a couple generations, work their way back up to Minnesota every year.


To find out more about Facebook commenting please read the
Conversation Guidelines and FAQs

Leave a Comment