MJV Webinar: Earth, Wind, and Fire: Impacts of Prescribed Burning and Extreme Weather events on Butterfly Populations in South Texas

Join the Monarch Joint Venture for the July session of the Monarch Conservation Webinar Series.

Title: Earth, Wind, and Fire: Impacts of Prescribed Burning and Extreme Weather events on Butterfly Populations in South Texas

Presenter: Rebecca R. Zerlin, Lab Manager for the Cariveau Native Bee Lab, University of Minnesota

Description: With insect pollinators being vital in every terrestrial ecosystem, land managers should consider improving pollinator habitat with their management efforts. One method of habitat management is the use of prescribed fire, which can be used to reduce dead herbaceous plant matter and promote new, highly nutritious plant growth. We examined the effects of varied prescribed burn intervals and seasons on butterfly populations in coastal south Texas grasslands. Patches at least 500 acres each were treated with summer or winter burns on either 3- to 5-year intervals, or no-burning (control). Beginning in March 2020, we conducted monthly butterfly surveys for two years to determine the effects of burning on butterfly abundance and diversity. We found no effect of winter burning, but summer burning sometimes reduced butterfly abundance or diversity.

Over the course of the study, our field site was directly hit by Hurricane Hanna in July 2020 bringing 14 inches of rain within a 24-hour period, and received extreme below-freezing temperatures over a 3-day period during Winter Storm Uri in February 2021. We found that the atypical, prolonged winter freeze resulted in significant reductions to butterfly populations, but the Category 1 hurricane had no effect. With climate change leading to more frequent droughts, freezes, hurricanes, and other extreme weather, it is important to examine the impact that these events have on pollinators, and to consider the effects of management actions within the context of extreme weather.

Bio: Rebecca is the lab manager for the Cariveau Native Bee Lab at the University of Minnesota. She received her B.S. in Wildlife and Ecology at Unity College in Maine and M.S. in Rangeland and Wildlife Management from the Caesar Kleberg Wildlife Research Institute at Texas A&M University – Kingsville. Her master’s research looked at the effects of different prescribed burning intervals on butterfly populations in south Texas. Rebecca has worked with a variety of organizations including the Bureau of Land Management, the Cape May Bird Observatory, and the National Park Service. Her research interests include examining the impacts of management practices on threatened and endangered insects, particularly butterflies and bees.