A mesa is a flat piece of land surrounded by gulleys. Mesa means “Table”, and they look like that, like big stone and dirt tables. In some areas of the American southwest the flat spot on top of the mesa is good grazing land, and it’s not uncommon to find a herd of sheep grazing away.

Nearby is a similar mesa, with goats on it. There are also wolves, and the wolves sometimes kill and eat a goat. The goats will at least try to defend themselves, if cornered, and many a wolf retains cracked ribs as a result of a goat encounter.

A bridge is built between these mesas. it’s all good, right? the goats will come eat the weeds where the sheep graze, and the sheep will come and graze on the grass the goats leave behind (Lots of goats prefer weeds and brush to grass)

Also, the wolves cross over.

“What’s the big deal? The wolves eat goats now. it’s already bad if a wolf eats a sheep, the bridge didn’t make it more bad”

Predators are going to be predators. Why would we facilitate predation?