Enhancing Movement of Pronghorn in the Northern Sagebrush Steppe Through Testing of Fence Modifications, 2010–2024

Final Report


Paul F. Jones, M.Sc.

Amanda MacDonald, B.Sc.


Fences are a common feature on the landscape across the globe and were first used for hunting purposes. As people became more sedentary and reliant on an agriculture-based lifestyle, the proliferation of fences increased. Fences have been erected to delineate political boundaries (e.g., between countries), mark property boundaries, and to protect and manage resources (i.e., domestic livestock and wildlife). Although fences are ubiquitous on the landscape, their impacts on wildlife and ecosystems are invisible. There is an urgent need to understand and study the impacts that fences have on wildlife and ecosystems globally. Three species that are susceptible to fencing are pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus), and white-tailed deer (O. virginianus). Pronghorn may cross under fencelines in some locations, but it slows down their movement, making them susceptible to predators, and in some cases strips hair off their back, causing lacerations and making them vulnerable to infection and frostbite. Deer, while able to jump fences, risk being caught in the fence, resulting in direct mortality if unable to free themselves, or becoming injured from trying and successfully freeing their leg(s) from the fence.

We had three primary objectives for this project: 1) increase awareness within the scientific community of the potential impacts fences have on wildlife and ecosystem function and propagate the need for a new discipline called “fence ecology”; 2) evaluate the effectiveness of different bottom wire heights and fence modification techniques to enhance pronghorn and deer movements across fences; and 3) increase the profile of pronghorn, the proposed new discipline of fence ecology, and the need for wildlife-friendlier fencing standards through publications in peer-reviewed journals, landowner guidelines, and presentations.

Alberta Conservation Association was a contributing author for a monumental paper on fence ecology published in 2018, which has served as an awakening for the conservation community to the need to examine the impacts of fences on wildlife and ecosystems. Since that paper was published, there has been a proliferation of research and publications examining the impacts of fences. Our evaluation of fence modifications has resulted in a change of standards for wildlife-friendlier fencing. It is now widely acknowledged that a double-stranded smooth bottom wire set at 45 cm (18 inches) and a top wire height of 102–107 cm (40–42 inches) is the recommended fencing practice across western North America.

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