Seeing clusters of monarchs in trees? Here's what's happening

I love taking our black lab, Pepper, for long walks through the prairie we’ve established between the cornfields on our family farm. We often spot deer and pheasants near the little creek, and I usually come home with a handful of wildflowers for my daughter.

But this weekend, while Pepper had her nose to the ground sniffing everything in sight, something above us caught my attention: dozens of brightly colored monarch butterflies clustered in the trees.

A monarch rest stop

Monarchs migrating from Canada to Mexico fly during the day and gather in trees overnight to rest, forming temporary groups known as “roosts,” said Mykayla Hagaman, program coordinator for the Iowa State University Monarch Conservation Consortium, which Iowa Farm Bureau helped establish in 2015 and continues to support as part of monarch conservation efforts across Iowa.

The consortium has been asking Iowans to report sightings of these roosts to help researchers better understand where monarchs stop and what habitat they seek out along their journey. 

More than 500 roosts have already been reported this year. 

“We have a lot less knowledge about their habitat selection during this fall migration,” Mykayla said. “They do still need to feed on nectar plants. A lot of native flowers, like Asters or golden rods, are really key because they’re some of the last blooming flowers on the landscape, but we have a lot less knowledge about if they have a specific tree preference.”

Farms provide important habitat

Since 2015, Iowans have established more than 690,000 acres of monarch and pollinator habitat, reaching nearly 90% of the state's long-term conservation goal. More than 500,000 of those acres, or 72%, are on Iowa farmland.

On farms, habitat can be established on acres that are difficult or less productive to farm, including areas with sandy soils, uneven terrain or consistently low yields. Prairie strips, saturated buffers and native plantings through the Conservation Reserve Program can provide wildlife and water quality benefits.

“Iowa State has done some really good research showing if you incorporate prairie strips onto the margins of your cropland, it can help reduce soil erosion and filter out nutrients,” said Mykayla. “So, it helps with water quality, and of course, prairie strips support pollinators and other wildlife like birds.”

Plants that support monarchs

“The nice thing about monarchs is they can benefit from any size of habitat people want to establish,” Mykayla said. “Whether that’s prairie strips in agricultural areas, native pollinator gardens in urban areas or even a couple potted plants on someone’s porch.”

To support monarchs throughout their lifecycle, she suggests planting native milkweed, the only food source for monarch caterpillars, along with nectar-producing flowers that provide food for the adult butterflies. 

Knowing even a small pot of flowers could make a difference has me thinking about what I can plant at our home next year. The monarchs we're seeing now may only be passing through, but their brief stop has given me one more reason to pay attention to what’s growing—and flitting—around us.

Learn more about author Caitlyn Lamm here.