Pronghorn antelope undertake one of the longest remaining land mammal migrations in the Western Hemisphere, but their ancient routes face increasing fragmentation from fences, roads, and development.
Migration barriers cause welfare harm to pronghorn through multiple pathways. Animals that cannot complete migrations due to fence barriers face starvation when cut off from seasonal forage, particularly in severe winters when energy demands are highest. Pronghorn that attempt to cross barriers may injure themselves on wire or become entangled. Animals forced to winter in suboptimal habitat experience nutritional stress, increased predation risk, and reduced reproductive success. The welfare implications extend through populations when migration disruption causes herd-level nutritional failure during harsh winters. Fence modifications and wildlife-friendly infrastructure design are cost-effective interventions that allow pronghorn to maintain their ancient migration routes.