OutdoorNebraska

7 Surveying for Rare Butterflies By Cody Dreier, Pollinator Ecologist, Nebraska Game and Parks Commission M any studies show that butterfly populations have been declining throughout North America over the last 30 years. In particular, two native butterflies in Nebraska, regal fritillaries (Speyeria idalia) and monarchs (Danaus plexippus), are under consideration by the U.S. Fish and Wildlife Service for being listed as endangered species under the Endangered Species Act. In 2016, the Nebraska Game and Parks Commission started a long-term monitoring project to collect information on these two species in Nebraska. Through this project, professional biologists and citizen scientists work hand in hand in eastern Nebraska to identify the butterflies and flowering plants that are actively blooming and serving as butterfly nectar sources. Regal fritillaries are a non- migratory species and reproduce only once each year. The caterpillars of regal fritillary butterflies only eat violets, like prairie violets and bog white violet. In contrast, monarch butterflies are a migratory species and spend the winter in Mexico. They have three to five generations a year and the caterpillars only eat milkweed plants. Luckily, both regal fritillaries and monarchs are relatively easy to see and identify. This makes them great species to use in citizen science, in which the public assists with the collection of scientific data. For this project, professional biologists or citizen scientists walked transects (designated survey lines through prairie and forested areas) and counted the butterflies they saw. They recorded the distance and angle to the butterfly. With a little bit of trigonometry, we can use these numbers to learn the approximate abundance of our target butterfly species. This will help us understand where the population actually stands in Nebraska and could aid in the federal listing decision. During the summer of 2020, the project was able to survey nearly 200 sites from mid-June to mid-August. With the limited timeline of fieldwork, citizen scientists proved to be a highly valuable addition to the team as they surveyed over half of the 200 sites. We have already been able to document over 300 individual rare butterflies and over 100 unique plant species along the survey transects from 2020, and analysis of the data will continue in 2021. This project is not finished yet, and the best way to stay up-to-date is to like and follow the Nebraska Monarch and Pollinator Initiative page on Facebook. Game and Parks is always looking for more volunteers and can help you find the citizen science project that is right for you. Feel free to contact the author at cody.dreier@nebraska.gov or 402-417-1755. PHOTO BY ERIC FOWLER Many butterfly species require a specific host plant when in the larval stage, like the monarch caterpillar's reliance on milkweed plants. Monarchs become generalists once they emerge as butterflies and will nectar on most any plant they can find, like this adult monarch nectaring on a coneflower. Coordinating wildlife biologist Jen Corman documents flowering plants that are blooming during a survey of habitat for rare butterflies. Landowner and citizen scientist Allyson Dather assists with documenting the variety of plants during a butterfly habitat survey. PHOTO BY ALLYSON DATHER PHOTO BY JEN CORMAN

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