I hand-fed one through a fence in New Zealand. The fence seemed feebly inadequate if the beast was determined to escape. This beautiful, large, shaggy-headed beast was, however, very gentle, much like a regular cow.

I know a bison rancher. They have problems with them jumping the fences. He's got 5 foot tall fences, and some of them can jump the fence without touching it. They could plow right through it if they wanted, but they prefer to jump.

Only tangentially related, but we had a funny incident when an American visitor staying with us told us about his visit that day to a wildlife park here in NZ.

He and his wife spotted a hole in the wire netting fence enclosing the lions.

They assured each other it couldn't really be a hole - after all, the park owners would be sued up the wazoo if they actually left a hole in the fence, such that a lion could potentially escape and maul a visitor.

So they crept closer and closer until they realised that yes, it really was a hole and no, there was nothing else restraining the lion within.

I explained to him after all this that sueing people was not really a thing here, and he should assume that any such holes were just that - an actual hole.

Fences at zoos are generally for the visitors.

Modern zoo design largely uses things like moats to contain the animals, as they can be hidden from visitors and need dramatically less maintenance.

I live by a large-ish herd of farm raised Bison. I've gone to visit them a few times, mainly because they boarder a national forest with great trails. They're big as heck, when they run as a herd you can feel them. Truly impressive animals.

Its pretty terrifying to look out of your sedan at a herd of 100 bison, they are BIG.

They do a lot of Bovine farming in Australia... and they have enough trouble keeping them in their paddocks... how the hell do they make herds of say 100 Bison stay in their paddocks?!?