Thanks for these shots. At first glance Chlidonias' suggestion of tonkeana seems most likely, but these animals are very pale underneath. They certainly have the look of being one of the Sulawesi species, but don't quite fit any of the ones I'm familiar with.
Colobus you are correct this animal is definitely a Mangabey and as there are other known White Collared Mangabeys in private ownership in the USA I agree with you entirely.
Sorry - we were being completely misled by them being labelled as 'grey-arm macaque' - honestly never occured to me to think they would be that far out! Just shows, never believe what you're told!
To be fair - I have another photo later elsewhere in this gallery that's of a monkey labeled white collared mangabay. I didn't have a photo of a sign to go with this monkey and the photos weren't clear which is why I didn't post them originally. But when the discussion came up on the sloth photo, I thought this must be the gray armed macaque, given the short tail and the light gray coloring on the front of the arms.
