Winged Road Warriors

August 15, 2019

Researchers track migration of monarch butterflies to determine whether roadside milkweed - often laden with salt - can fuel their journey.

Emilie Snell-Rood with monarch

Winter seems like a long ways off, but some are already beginning their migration south. Several thousand monarchs reared on the St. Paul campus are gearing up for their journey to central Mexico. Extra eyes are watching their journey this year.

Emilie Snell-Rood, an associate professor in the College of Biological Sciences, is preparing to release butterflies. The research explores how road salts impact the survival and migration of monarch butterflies. 

Since monarchs commonly eat roadside milkweed, the study will help researchers better understand whether this food sources is a healthy one. “Sodium in road salts is interesting because small amounts can be beneficial [to the insect] because it’s an important micronutrient, but large amounts can be toxic,” Snell-Rood says. A huge community of citizen scientists dedicated to tracking monarchs, known as Monarch Watch, allows an unprecedented opportunity to track survival and movement in the wild.


Get Involved! 

Follow the Release - A few alumni and members of the local community will gather to hear about the research watch the release Tuesday, August 20 at 11 a.m. Follow along on social media on Twitter and Instagram @umncbs.

Get Involved as a Citizen Scientist - Watch for monarchs in the area with colored tags on their wings and report your sightings. Any resighting provides important data on survival and movement in the wild. Report monarch sightings.

Support the Lab - For this project to be as successful as it can be, the lab needs your help to send a few grad students and postdocs to visit the over-wintering grounds in Mexico. Contribute.


A Step-by-Step Peek

Follow umncbs on Instagram and tune into “Monarch Journey.”

Step 1: Collect about a hundred monarch eggs from the wild and raise them. These butterflies lay thousands of eggs over their lifetime and researchers collect their eggs for the experiment. This means they don’t have to collect thousands of eggs from the wild.

Step 2: Collect thousands of milkweed stems from Cedar Creek Ecosystem Science Reserve to prepare for hungry caterpillars. It takes hundreds of pounds of milkweed to raise 3,000 caterpillars. This is barely  this is barely a dent in the amount of milkweed in a several acre site at Cedar Creek.

Step 3: Raise monarch caterpillars on milkweed with different levels of “saltiness.” Since milkweed is commonly found on roadsides, plants take up salts used during the winter months. To imitate this, researchers spray the milkweed leaves with salt water, mimicking a moderate traffic roadside (1000-2000 cars/day) and a high traffic roadside such as the I-35 corridor. 

Stage 4: Following emergence, researchers affix identification tags to the butterflies’ wings. As part of a large-scale citizen science program called Monarch Watch, citizen scientists report sightings along the way. 

Step 5 (pending support): A few grad students and postdocs hope to visit the over-wintering grounds in Mexico to increase resightings. Contribute to the crowdfunding campaign.

Stage 6: Results will help inform best management practices and restoration priorities along roadsides in Minnesota and along the “Monarch Highway,” which runs along I-35 spanning from Minnesota to Texas. - Claire Wilson