Ah - I remember these well! Necessary, as well, given the number of squirrel monkeys that descended around us.
Better put your specs in here too unless you want a thieving woolly monkey taking them up to the top of a tree...
@Pygathrix, the woolly monkeys won't do that anymore, the aren't aloud to leave their island anymore now.
@lintworm, I know. I have only been twice, the first time there was a lot more interaction with the animals, for example people were allowed/encouraged to let the squirrel monkeys run over their shoulders, heads, and arms, and the woolly monkey area was walkthrough. The second time I went I asked a keeper about this, she said there had been a few bites etc and they had stopped all that for fear of legal repercussions. That's a shame because the squirrel monkey experience was really quite special. You were never allowed to feed them and they could easily go to a different part of the large enclosure, so I think for the monkeys it was positive enrichment too.
The policy has become less rigid then 4 years ago now and the monkeys are aloud again to interact with the visitors, but the visitors aren't aloud to do anything and there are now lots of volunteers in the free-ranging area watching everything. And especially the squirrel monkeys are very interested in people sometimes.