It now looks like a forest. How it used to look:
http://www.zoochat.com/1550/wild-amazonia-squirrel-monkey-forest-315734/
The park is concerned about the monkeys getting too bold, jumping onto people and biting. The opening hours of the walk-through have been shortened to allow at least one staff member to be present at all times. Keepers have also been conditioning the monkeys to avoid humans.
