Pronghorn are the fastest land animals in the Western Hemisphere, yet their migrations are being blocked by fences. Understanding the welfare impacts of habitat fragmentation guides more effective conservation.
Pronghorn welfare illustrates how infrastructure decisions made without wildlife in mind impose significant welfare costs on animals that evolved in open, fence-free landscapes. A pronghorn unable to complete its migration faces progressive starvation as winter depletes forage on summer ranges where it cannot leave. Pronghorn that attempt to crawl under fences may become entangled, leading to injury and death. The welfare consequences of fence barriers are not hypothetical — documented population crashes have occurred when migration routes were blocked during severe winters. The solutions are technically simple and economically modest: raising bottom fence wires by 30cm from the ground allows pronghorn to pass freely while continuing to contain cattle. Wildlife crossing programmes that modify fences at key migration bottlenecks have measurably improved pronghorn movement. The challenge is coordinating fence modification across the patchwork of private, state, and federal land ownership that characterises western landscapes.