Wild horses, like other animals, take their cues from their environment. If a herd is to regulate its own size, it needs a feedback loop that compares the current state of affairs to the desired state of affairs. The larger the gap, the greater the effort to close it.
Some observers have noted that roundups increase reproduction, which makes sense in view of the feedback model. The gap has increased and nature says ‘Fill your niche!’
If you drive a car, you’re already familiar with feedback loops.
The speedometer shows the current state. You compare that to the desired state—the speed limit—and act accordingly. If you’re merging onto a freeway, the gap is large so you ‘put the pedal to the metal.’
Now, suppose you step on the gas but nothing happens. Worse, suppose you hit the gas and the car slows down.
That’s what PZP does to the feedback loop.
A roundup tells the herd to hit the gas while the advocates are stepping on the brakes.
The helicopters and darts are flying not because the carrying capacity of the land has been exceeded but because the resource allocations have been violated. The horses are never allowed to seek their level.