Date: November 28, 2016
Time: 1:30 – 3 pm MST  / 12:30 – 2 pm PST
Hosts: USFWS Region 6 Science Applications
Presenter: Kelsey McCullough, Fish and Wildlife Cooperative Research Unit, Kansas State University

The regal fritillary (Speyeria idalia) was once an abundant butterfly species in North American prairie communities but populations have declined~99% for poorly understood reasons. Our research objectives were to assess the effects of management practices and habitat features on the distribution and abundance of regal fritillary and their larval host plants (Viola spp.). We surveyed remnant tracts of prairie in northeastern Kansas for regal fritillary host plants, larvae and adults. We applied these data to a novel gradient habitat model framework.

This approach facilitated the development of spatially-explicit models of the distribution and relative abundance patterns of regal fritillary larvae, adults and host plants as a continuous function of multiple resources and environmental conditions across multiple scales. Our results elucidate the potential of using species distribution models to efficiently locate patches of host plants and subsequently larvae within a large habitat matrix. Furthermore, our results indicate that greater host plant density and short fire-return intervals are important to the occurrence of late-instar larvae and despite current management recommendations, larvae may be negatively impacted by a lack of fire.

Finally, analysis of adult data suggests that adult density was at least 84% greater in areas that received moderate fire-return intervals and greatest in areas that were grazed and burned on a moderate fire-return interval. The conservation management implications of these results to the persistence of regal fritillary populations within the region may require a rethinking of previous assumptions.

About the presenter: Kelsey McClullough is a graduate research associate pursuing a Master’s degree in the Kansas Cooperative Fish and Wildlife Research Unit and Division of Biology at Kansas State University. Her research focuses on assessing the species distribution, effects of management practices (fire, grazing, and haying), and related habitat features for the regal fritillary butterfly (Speyeria idalia) and its larval host plant (Viola spp.). Kelsey has also incorporated research on the monarch (Danaus plexippus) butterfly into this project.