Wild and Domestic Sheep are Comingling, Raising Concerns Over Disease Transmission

by Sophie Tsairis

A five-year research initiative in Montana, is looking at the implications of wild bighorn sheep and domestic sheep interactions. The project, which began in 2024, seeks to understand the factors that influence the probability of contact between bighorn sheep and domestic sheep and goats. Ultimately, the research could help prevent disease transmission while supporting wildlife conservation and agricultural interests, project leaders say.

While still early in the data collection process, researchers for the Wild and Domestic Sheep Comingling Project have discovered significantly more domestic sheep and goats living in close proximity to bighorn sheep populations than expected, as well as more interactions between the species. 

Researchers for the project, led by Montana State University and Montana Fish, Wildlife and Parks, are inviting public participation through a series of community meetings this spring and seek domestic sheep producers to join the study.

Since 1941, when Montana began working to recover its dwindling bighorn sheep population, ranchers and wildlife managers have been trying to keep wild sheep and domestic sheep and goats separate. Among their concerns: the transmission risk of respiratory pathogens involved in pneumonia that largely affect wild populations and can be catastrophic to herds. Occasional instances of interbreeding between wild and domestic sheep, which results in loss of productivity for producers, were a secondary concern that prompted the study. 

The research involved a collaboration between MSU’s Animal and Range Sciences Department, MSU Extension, and FWP, with additional support from the Montana Wool Growers Association, the Montana Wild Sheep Foundation, and local producers.

"The overarching goal is to improve the ability of both wild and domestic sheep and goats to thrive on Montana's rangelands,” project leaders wrote in an email to Mountain Journal. “We're not directly measuring disease transmission, but rather getting a better understanding of when, where, and how often wild and domestic sheep come into contact — and what environmental or biological factors influence those interactions.”

Funded through a Pittman-Robertson grant awarded to FWP, the study focuses on a subset of bighorn sheep herds where agency research is already planned or underway as part of its adaptive management plan. The team is using a variety of tools including husbandry surveys, GPS collars and trail cameras to monitor movements and assess contact risk between wild and domestic animals.

The collaborative group is hosting a series of public meetings across Montana this spring as a core part of its research model. "[The meetings] aren’t just about sharing project updates,” the researchers said. “They're also a chance to invite new producer participation, listen to local concerns, and gather feedback from stakeholders across the sheep community.”

The conversations are open to the public and the study’s team says the meetings are meant to ensure the study reflects real-world conditions and local values while building trust across diverse interests. 

· May 6, Wolf Creek: 5:30-6:30 p.m., Wolf Creek School, 150 Walsh Street

· May 15, Thompson Falls: 5:30-6:30 p.m., Elks Lodge, 2519 Industrial Way

· May 20, Dillon: Noon-1 p.m., Beaverhead County Fairgrounds 4-H Building, 715 S. Railroad Avenue

· May 20, Twin Bridges: 5:30-6:30 p.m., Madison County Fairgrounds Jeffers Building, 2 Fairgrounds Loop Road

· May 29, Emigrant: 5:30-6:30 p.m., Emigrant Community Hall, 3 Story Road