And bear in mind that the squirrel monkeys at Edinburgh are part of Living Links - the primate research centre - so it may well be necessary to be able to confidently identify individuals at a distance.
Right ..... if it's to ID it then that's understandable, and far preferable of course to the animal getting hold of something it shouldn't. I've never noticed anything similar anywhere else though, even if Chester's lemurs have them.
I would believe it is to ID.
All I can really add to this, was that the Living Links keeper that I talked with didnt bat an eyelid about that one wearing it when he examined that one in the window.
Although I didn't think at the time to ask about the neckless. Can always do that on another visit
It is indeed to assist identification. The cappuchins are easier as they do have noticable differences, but the squirrel monkeys are very similar and move so fast. They are also microchipped should something happen to the necklaces. ID boards at the enclosure also refer to the necklaces. A similar thing is used on the ring tail lemurs.
Dudley Zoo also does this in their "Monkey Tails" walk through with these monkeys - it can show who is who and who is related to who and who comes from where =)