Habitat & Conservation  |  06/21/2018

A Corridor for Conservation


Interstate 35 – known as “The Monarch Highway” – cuts through the heart of pheasant and quail country

By Jason Jenkins

Each fall, the monarch butterfly embarks on what many consider to be nature’s ultimate road trip. Despite weighing less than a gram (about as much as a standard paperclip), monarchs that hatch as far north as Minnesota and Canada pack their proverbial bags and hit the road to their overwintering grounds in the oyamel fir forests in the mountains of central Mexico. 

What makes the feat all the more incredible is that the insects fly thousands of miles to a place they themselves have never been, a place last seen by the migrating butterflies’ great-great-grandparents.

A Species in Decline

During the past 20 years, however, the number of monarchs taking this road trip has drastically declined — by as much as 90 percent. Loss of habitat across their breeding grounds, untimely mowing, pesticides and illegal logging in their overwintering grounds have all contributed to the population decrease. 

In 2014, the U.S. Fish and Wildlife Service (USFWS) was petitioned to protect the butterfly under the Endangered Species Act, and the insect currently is being evaluated for listing. While that decision is due in June 2019, monarch conservation efforts already have increased throughout North America.

The Monarch Highway

This is especially true along the migration route, which coincidentally, mirrors the path of U.S. Interstate 35 from Duluth, Minnesota, to Laredo, Texas, a journey of more than 1,500 miles. The road has been informally identified as the “Monarch Highway.”

“The effort really came out of the ‘National Strategy to Promote the Health of Honey Bees and Other Pollinators’ released by the White House in 2015,” says Tina Markeson, roadside vegetation management unit supervisor with the Minnesota Department of Transportation. “That document identified I-35 as a corridor that could serve as a focal point for linking resources and coordinating actions. Six states agreed to work together, share data and other information about increasing pollinator habitat on rights of way.”

The collaboration involves the departments of transportation in Texas, Oklahoma, Kansas, Missouri, Iowa and Minnesota as well as the U.S. Department of Transportation and the USFWS. 
Markeson says that across the board, all those involved have been reexamining their seed mixes and how they can make them friendlier for pollinators, especially incorporating more milkweed species, which are host plants for monarch butterflies.

“Maintenance has also been an area where we’re learning from each other,” she said. “Here in Minnesota, we have a prescribed fire program that we use to maintain the quality of native grass and pollinator habitat, and other states have been using it. Others have been cutting back on mowing in their rights of way.”

Rest Areas for People and Monarchs

Rest areas along I-35 also have been a focal point, combining both habitat and education in one place. Markeson says that just north of the Twin Cities, for example, a new rest area under construction is slated to have pollinator habitat seeded on its grounds as well as a garden display near the building where travelers can learn more about the monarch and its conservation.

“The Goose Creek Rest Area will be MDOT’s first to be registered in Monarch Watch’s waystation program, and we’re looking to incorporate more,” she adds. “Thanks to the Monarch Highway name, we’re hearing from different groups and landowners who want to help, which is great. It’s going to take everybody working together to turn around the monarch population.”

The Monarch Joint Venture

Cora Lund Preston works for the Monarch Joint Venture (MJV), a national coordinating body that works to facilitate efforts in monarch habitat conservation, research and monitoring, and education and outreach. She agreed that the I-35 collaboration is serving as a catalyst for broadly engaging the public about the issue.

“The Monarch Highway is a great example of how partnerships can happen across state boundaries,” Preston says. “It’s really helped people understand the migration route and is energizing monarch conservation throughout the entire flyway region, even beyond those who are adjacent to the interstate.”