Cooperative Fish and Wildlife Research Units Program:
Education, Research and Technical Assistance for Managing Our Natural Resources


Factors Limiting Population Growth of Unhunted Dall’s Sheep

January 2023 - December 2025


Participating Agencies

Despite nearly a decade free of harvest pressure, sheep populations in northwest Alaska have not rebounded as anticipated. Identifying the factors that continue to repress these populations will aid in the general understanding of Dall sheep ecology and help inform how sheep populations, at the margins of their range, can be sustainably managed in the future. Determining the relative effects of these factors can assist managers in determining appropriate harvest seasons and bag limits and identifying critical landscape features and areas requisite to sheep’s continued presence in GMUs 23 and 26.

We will radio-collar approximately 20 sheep in each of two herds (De Long, Baird) in the fall/winter of 2023 and 2024. Mortality will be monitored via movement data and mortality sites will be visited as soon as possible to attempt to determine mortality cause. If possible, tissue samples will be collected for additional analysis. Health assessment will be conducted during capture and biological samples collect to analysis for disease, genetics, pregnancy, and nutritional limitation. Collared ewes will be radiotracked with fixed-wing aircraft weekly between May and June to determine lambing rates using the presence of a lamb at heel.

This study will be the first to quantify habitat use patterns, survival rates, and health of sheep in these herds. This project will provide ADFG with the information needed in order to manage both of these sheep herds in order to improve population trajectory.