This article was based on this USGS press release about the study.
A recently published study has found that everyone has a role to play in restoring the eastern monarch population. Scientists from USGS, the University of Arizona and other partners developed scenarios for sector-based involvement in monarch habitat restoration. In other words, they looked at which societal sectors, or combination of sectors, could have the most positive impact for monarchs through the creation of habitat. After looking at five sectors (Conservation Reserve Program lands, utility and transportation rights-of-way land, agricultural lands and urban/suburban lands), they found converting marginal cropland to monarch-friendly habitat provides the best opportunity to restore the eastern migratory monarch population. However, in addition to agricultural lands, the authors emphasized that planting milkweeds into other kinds of lands, including protected areas and urban and suburban locations, will be necessary.
“The main finding of our study is that an all-hands on deck approach could be essential to restoring the massive amounts of milkweeds needed to make the monarch population healthy again,” said Wayne Thogmartin, a USGS scientist and the lead author of the report. “These findings offer great hope for citizens from all sectors working together to reverse the substantial decline of these iconic butterflies.”
This study builds on another recent report that suggests approximately 1.8 billion additional milkweed stems may be needed across North America to return eastern migratory monarchs to a sustainable population size. As monarch conservation activities and collaborations continue to expand, these studies will bring focus to where we can be most effective in getting those milkweeds (as part of diverse, nectar-rich habitat) in the ground.
This image shows a monarch larva, or caterpillar, on milkweed. Milkweed plants are the only plant species that provides breeding habitat and food for monarch young. (Photo by Wendy Caldwell.)
Thogmartin said that converting at least half of the marginal agricultural land in the Midwest to monarch-friendly habitat could result in a full population recovery. However, he said, an approach that doesn’t rely solely on agricultural lands would be more robust. The research demonstrated that the non-agricultural sectors combined could provide as many as 800 million stems of milkweed, a large contribution to conservation, while agricultural lands restoration will still be critical to reach enough milkweed to accomplish our national target of 1.8 billion additional stems. Ultimately, habitat across all sectors will contribute to our goal of growing the eastern monarch population to at least 6 hectares of area occupied in their Mexican overwintering grounds by 2020.
"Encouraging urban and suburban areas to participate along with the agricultural sector could create a crucial spark of public support and momentum for monarch conservation across the board,” said Laura López-Hoffman, a conservation biologist at the University of Arizona who co-authored the study.
Everyone has a part to play in the monarch recovery. You can make a difference for monarchs today, so find out how to get involved here. Research confirms that we need all hands on deck, including yours!
For more information about monarch butterfly research, visit the USGS Monarch Conservation Science Partnership website.
Please note that in the Western U.S., The Xerces Society for Invertebrate Conservation recommends against planting tropical milkweed, and generally suggests a 5-10 mile rule for planting native milkweed on the Pacific coast. However, an exception is made for far Southern California where milkweed historically occurred closer to the coast. These recommendations are based on the historical occurrence of milkweed---you can see a summary of the available data and recommendations in the Xerces State of the Overwintering Sites Report.
“Restoring monarch butterfly habitat in the Midwestern US: 'all hands on deck',” was published June 29, 2017 in Environmental Research Letters, and authored by Wayne E Thogmartin, Laura López-Hoffman, Jason Rohweder, Jay Diffendorfer, Ryan Drum, Darius Semmens, Scott Black, Iris Caldwell, Donita Cotter, Pauline Drobney, Laura L Jackson, Michael Gale, Doug Helmers, Steve Hilburger, Elizabeth Howard, Karen Oberhauser, John Pleasants, Brice Semmens, Orley Taylor, Patrick Ward, Jake F Weltzin and Ruscena Wiederholt.
The Monarch Joint Venture is a national partnership of federal and state agencies, non-governmental organizations, and academic programs working together to conserve the monarch butterfly migration. The content in this article does not necessarily reflect the positions of all Monarch Joint Venture partners. Header photo by Candy Sarikonda.