Monkey escape surprises scientists

This is Japan, there are 80 monkeys confined by a 17 foot high electric fence around a forest preserve of unknown dimensions, but the idea of the scientific study is to study the monkeys in a natural habitat, so possibly the area enclosed is quite large. Regardless of the size, the confinement is much nicer than the American universities I have heard of. So the link above is to the story, about 15 monkeys who get over this electric fence by, using the top branches of a tree to fling themselves over the fence. Like pole vaulting. All 15 monkeys.
The scientists recaptured them by coaxing them back in with peanuts. The scientists appear clueless about why the monkeys escaped, and so I am going to continue some comments perhaps in the American Mysticism blog.