Pronghorn antelope in northern Arizona were having a hard time moving freely through the area. Highways, railroad tracks, and fences were preventing these fast animals from exploring their habitat. Wildlife biologists and volunteers decided to make it easier for the pronghorn antelopes to move around by adjusting the barbed wire fencing along a 5-mile (8 km) stretch. Pronghorn antelope can jump, but they prefer to go under fences. When they moved under the barbed wire fences, it damaged their horns which was bad for their health.