Spotlight on the Ruden Lab
Dr. Rachel Ruden
Affiliate Associate Professor
Department of Veterinary Diagnostic and Production Animal Medicine
Research Area
Dr. Rachel Ruden is the state wildlife veterinarian with the Iowa Department of Natural Resources and has a joint appointment with the Department of Veterinary Diagnostic and Production Animal medicine. She focuses on understanding the risk landscape affecting wildlife health in Iowa from new threats like highly pathogenic avian influenza to ongoing concerns like heavy metal poisoning. Dr. Ruden’s research has prioritized disease blindspots including “where we need more investment in sampling and monitoring to evaluate impacts, or even relevancy, of a given pathogen on the wildlife resource.”
Dr. Ruden has worked with a number of collaborators since 2022 to better understand the spatial extent of Pseudogymnoascus destructans (Pd), the fungus that causes white-nose syndrome (WNS) in Iowa. She uses a passive surveillance technique developed by the U.S. Geological Survey to test guano (bat poop) for the presence of this pathogen, which individuals from exposed colonies should groom off their bodies after emerging from hibernation in the spring. A natural extension of this work, Dr. Ruden started a live bat sampling project this year at a group of sites with a history of Pd-positive guano.
Origins
Dr. Ruden became interested in bat work due to a knowledge gap. “Much of the work around white-nose syndrome emergence in North America has focused on tracking the leading edge of infection,” she says, “but we had very poor resolution of the true risk landscape in Iowa where four of the state’s five resident bat species are or may soon be protected by the Endangered Species Act. I felt an obligation to improve our knowledge base.”
Funding
- The guano surveillance portion of Ruden’s bat project was supported by the U.S. Fish and Wildlife Service through their White-nose Syndrome Grants to States and Tribes, 2023-2025
Publications
A number of manuscripts are anticipated from Ruden’s research including results from five years of guano surveillance across Iowa.
Results
The passive surveillance project leveraging bat guano has detected the fungal pathogen that causes WNS in four eastern Iowa counties where no previous baseline data existed. This past spring, Ruden’s group captured 102 little brown bats at one location that has tested consistently positive for the pathogen since 2022. Sampling and tagging individual bats should allow researchers to better understand the “cost” of pathogen exposure on metrics such as activity levels and possibly even reproduction.
Research Team
Rachel Ruden
Graduate Student: Faith Hansen
ISU Collaborators: Veterinary Diagnostic Laboratory including Dr. Phil Gauger and Laura Bradner
Other Collaborators: County Conservation Board staff, Iowa Department of Natural Resources, private partners, Jones County Conservation and Dr. Russ Benedict (Central College)
September 2026