DNS, you're at the zoo, read the signs. Brilliant. Why didn't I think of that? Of course, I'd have been standing around with plenty of time beforehand to read signs, we can just assume that...
But, if we are assuming that, we should also assume I'd have pulled the child off the fence before he had a chance to fall, and thoroughly chewed out the mother. So maybe we should not assume time in advance to read signs, eh?
Feeding the animals in such a way that they can "hunt" and "kill"? Really?
I've been to the Central Park Zoo when the polar bears were fed. True, the keepers want to keep the animals from getting too bored. At the same time, they don't seem interested in setting up potential fights amongst the bears, and I doubt most New Yorkers would be thrilled with the keepers tossing in a seal pup or similar.
What they actually did was place fish in polyurethane balls that had the tops cut out, kind of like pumpkins to jack-o-lanterns. They poured water in around the fish, and froze the balls. The bears had to bat and paw the balls around enough to break the ice sufficiently that the ice and fish could fall out of the ball. This was their simulated hunting and killing.
If you've seen a public zoo that actually conducts feeding in a way that would emulate prey activity, and force predators to battle over their food, please cite the zoo, the critters, and the method.
I've only been to the Central Park, National (DC), San Diego zoos, and Busch Gardens (Tampa) preserve and Lion Country Safari. I've never witnessed the type of feeding methods you suggest.