Since 2019, the Monarch Joint Venture (MJV) and National Fish and Wildlife Foundation (NFWF) have collaborated on an extensive project to monitor monarchs and their habitat across the eastern U.S. The findings, described in more detail below, are building a picture of the positive impact conservation can have on breeding and nectar resources for monarchs, as well as the monarchs themselves. All told, these findings demonstrate substantial, quantifiable successes for monarch conservation!
In 2015, NFWF established the Monarch Butterfly and Pollinators Conservation Fund (“Pollinator Fund”), a program to advance the conservation of the monarch butterfly and other at-risk insect pollinators. Through the program, Pollinator Fund grant recipients have restored or enhanced over 336,000 acres of pollinator habitat (that’s nearly half the size of Rhode Island!), and the program has supported new partnerships, planning efforts, and seed production.
In addition to tracking the acres of habitat it improves, the Pollinator Fund also measures the impact these acres can have on monarch habitat and populations. Quantifying the program-wide impact, however, was beyond the scope of individual Pollinator Fund grant recipients. Thus, NFWF and the MJV collaborated to evaluate many of these project sites using the Integrated Monarch Monitoring Program (IMMP). The IMMP is a robust monitoring protocol managed by the MJV and used by hundreds of people nationwide to monitor monarchs and their habitat.
From 2019 through 2021, MJV field crews visited 182 sites across 12 states (Figure 1). Crews followed the IMMP protocol to record habitat (blooming plants and milkweed) and monarchs (eggs, larvae, and adults). Many of these sites were visited multiple times to better reflect habitat resources and monarch use throughout the season. Additionally, the MJV engaged community scientists and Pollinator Fund grant recipients in monitoring so they can continue expanding their knowledge of their own sites.
Based on IMMP findings, the Pollinator Fund projects are contributing between 35.5 million-153.9 million milkweed stems to the 1.3 to 1.8 billion new stems needed to achieve national monarch population goals. That represents 3-12% of the Mid-America Monarch Conservation Strategy's goal! Milkweed averaged 1,052 stems per acre in the north, and 324 stems per acre in the south (Figure 2). Notably, this is much higher than the 250 stems per acre that are assigned to restored grasslands in the U.S. Fish and Wildlife Service’s Monarch Conservation Database, which tracks monarch conservation efforts nationwide. This suggests that using the IMMP or other robust monitoring protocol may demonstrate that sites are providing more breeding potential than previously estimated.
Ninety-one percent of sites contained milkweed (95% in the north, 77% in the south), and in 2021, all sites had at least three native blooming forb species in each spring, summer, and fall survey. This is important because monarchs need nectar available throughout the entire breeding season, and one of the Pollinator Fund’s goals is to provide this resource. Northern sites were more species rich, averaging 37 species per site (25 native species), and southern sites averaged 17 species (10 native). Despite a big difference in the number of nectar species available, the north and south had comparable nectar resource availability - that is, in either region, there was about a 55% chance of a nectar resource being in bloom in any square meter of the site.
Adult monarchs visited at least 79% of sites, and bred on at least 67% of all sites surveyed. This is a conservative estimate because many sites were just visited one time, and reproduction may have occurred outside of that survey window. In 2021, MJV staff surveyed two dozen Midwestern sites on a weekly basis to take a closer look at monarch reproduction. Based on the timing and stages of larvae found, at least 75% of those sites likely produced adult monarchs to join the fall migration.
The most commonly used nectar species were wild bergamot (Monarda fistulosa, native), red clover (Trifolium pratense, nonnative), spiny plumeless thistle (Carduus acanthoides, nonnative), Canada goldenrod (Solidago canadensis, native), and eastern purple coneflower (Echinacea purpurea, native). This doesn’t necessarily indicate preference by monarchs; the plants may just be the most abundantly available. Fortunately, the IMMP dataset is available to researchers who want to take a deeper dive into monarch nectaring preferences or any other more detailed study question.
Each year, MJV staff invited grant recipients, land managers, and volunteers to learn the IMMP so they could conduct surveys on their own sites. MJV also created online training videos that are available to everyone here. More than 75 people were trained, including MJV partners Missouri Prairie Foundation and the Natural Resources Foundation of Wisconsin. After training, many conducted their own surveys after MJV staff left the area.
All told, between 2019 and 2021, Pollinator Fund grant recipients and their volunteers conducted 105 IMMP activities on 28 sites! Many of these participants are continuing monitoring in 2022, helping to grow a nationwide dataset of monarchs and their habitat, and also developing a track record for their own conservation sites.
The MJV continues to support all IMMP users, including Pollinator Fund grant recipients. Anyone interested in learning more about their conservation site, tracking progress over time, comparing outcomes among restoration sites, or generally contributing to knowledge of pollinator habitat is encouraged to check out the IMMP webpage and contact the MJV at firstname.lastname@example.org with any questions.
2021 marked the most recent field season of surveying Pollinator Fund habitat in the eastern monarch breeding range. Throughout this period, the MJV was able to work with and support partners involved in Pollinator Fund projects, including Fort Hood Adaptive and Integrative Management Program, Houston Wilderness, Mississippi Valley Conservancy, Missouri Prairie Foundation, Missourians for Monarchs, Pollinator Partnership, the Sand County Foundation, Three Rivers Park District, and the U.S. Fish and Wildlife Service, who helped connect MJV staff to their sites, contributed data to the broader project that will benefit monarch conservation going forward, and showed that large-scale, partnership powered conservation efforts really do make a measurable difference.
In 2022, the MJV is gathering data on sites in the western monarch range, throughout California from Napa to Los Angeles counties and the Central Valley, in southwest Oregon, and in Arizona through a partnership with the Southwest Monarch Study. Learn more about the MJV’s 2022 California monitoring projects here. Ultimately, this extraordinary collaborative monitoring and training effort is helping NFWF track progress toward its own goals, empowering Pollinator Fund grant recipients to lead monitoring on their Pollinator Fund sites or elsewhere, and expanding the knowledge base and dataset used to achieve national monitoring goals.
Since 2015, the Pollinator Fund has received support from partners including Bayer Crop Science, BNSF Railway, Scotts Miracle-Gro Foundation, Shell Oil Company, the Bureau of Land Management, U.S. Department of Agriculture, U.S. Forest Service, U.S. Geological Survey, and U.S. Fish and Wildlife Service.
Photo credits: Wendy Caldwell, Laura Lukens, Harry Rose/Flickr, and Leah Doyle.