Demons, Tigers, Pegicornitaurs.

What keeps tigers from eating the last deer?
They're hard to catch. Most chases end in failure.
Even lions, who hunt in coordinated attacks, in savannas
(where the prey is in full view and has nowhere to hide)
are limited thus.

Pegicornitaurs are not really equipped for grazing, yet they need to feed a body the size of a horse. Therefore they spend most of the day ambling, in search of seeds, berries, tubers, mushrooms, watercess, and so on. They share their habitat with grazers and rooters and rodents and their predators, including the likes of our Smilodon, who would relish the flesh of a Pegicornitaur, but has probably learned to avoid them. A single zap of electric shock is usually enough, but every year fresh Smilodons need to be taught, so Pegicornitaurs must always be on guard and never let their batteries fizzzle.

Thus far, there has never been a concerted effort to exterminate the Smilodon. The matter has been discussed, again and again, and the decision always comes out to let things be, because otherwise the other herbivores will ultimately devastate the land.

[Original illustration by Valedhelven, in storage, alas.]
These half-dragon demons, however, are a new and very different kind of threat. They have not yet devastated their own habitat, up north: a vast tropical rainforest where all sorts of edibles can hide. But, they are much more effective as predators than a tiger:

they are brainier;
they kill at a distance;
they fly;
they'll strike in darkness, silently. Success. No chase.

Had they also a banding instinct— urgh! I shudder. Fortunately for Pegicornitaurs, their mentality is closer to a tiger's than a wolf's. Only on rare occasion has one ventured this far south.

The only practical way to come here is to follow the coast, eating whatever you can pick out of a tide pool —which is not their culinary preference— and then there is the problem of diminishing freshwater, so, for someone accustomed to rainforest resources and climate, pressing southward, to landscapes ever bleaker, requires exceptional motivation and foolhardiness.

Imagine attempting a 4000-km trek down the West Coast of Africa, from the Equator to the southern tip. Could you survive the Skeleton Coast? (Yes, the sporadic solitary lion has been documented, scavenging the beach.)

On those rare occasions when a demon made it all the way to Pegicornitaur Territory, such an individual has either stayed to the end of its life (possibly, undiscovered!), or, if it ever made it all the way back, has considered it folly to divulge the existence of such a hunter's paradise!

But, sooner or later, a pregnant female makes it all the way down, gives birth, and then what? Or, a curious young female who has heard it from her mother, undertakes the journey, followed at a distance by a concupiscent male.

Having arrived, having feasted on the local deer, such male might want to impress the female by slaying a Pegicornitaur.

Oh, troubled times ahead!