A letter to The Nevada Independent suggests that wild horse herds will not grow beyond the capacity of their environment, so there is no need for sterilization, fertility control and other ‘solutions’ proposed by the government.
The idea is that growth rates taper off when the herds have filled their ecological niches.
What would trigger the change in behavior?
Would the horses sense that the limit has been reached when their habitat is dominated by livestock or would they make the determination based on their own kind?
Western Horse Watchers Association 