Crowding on the Range

In the Old West, there was well-documented antipathy between cattlemen and sheepherders, the result of disputes over grazing lands.  Dozens of murders (and the slaughter of thousands of heads of livestock) occurred across several states.  The arid western grazing lands, after all, once seemingly so vast, could only accommodate so many animals.  But the real conflict might not have been cows vs sheep - it may have been sheep vs sheep.  Or, more accurately, domestic sheep vs bighorn sheep.

Similar conflicts play out in Mongolia, with its Przewalski's wild horses, or the Sahel region of Africa, with oryx, addax, and gazelle.  Wherever there are grasslands with limited forage and water, there is almost inevitable conflict between domestic animals and the wild ones that were there first.  What is also inevitable is, the wild animals tend to lose.  

Farmers and ranchers monopolize dry country water supplies, limiting access to wild animals.  They erect fences, both to keep their animals in and others out.  Many hoofed animals, such as pronghorn, show a severe aversion to fences and will not attempt to cross them.  Others may try and die tangled up in barbed wire.  Farmers may shoot to kill or drive off native ungulates, seeing them as competitors to their livelihood.  When wild and domestic animals do mingle around water sources or grazing lands, the domestic animals may spread diseases to the wild ones, a major threat to the endangered desert bighorn sheep of the American Southwest.  In other cases, such as Przewalski's wild horse and domestic horses, or wild and domestic Bactrian camels, hybridization may occur. 

Like the wild animals that they compete with, arid-land pastoralists are often on the edge, trying to survive in dry, unforgiving climates.  Unfortunately, it's getting dryer and dryer, and therefore harder and harder for them to make a living, let alone coexist with wild neighbors.