A healthy diet of mealworms, fruit and veg ensures Saki monkey Rio has beautiful teeth as he’s keen to show but too many treats could lead to a big tum.
So keepers monitor Rio and his buddies, Obi and Deju, with regular weigh-ins and have trained the small primates to sit on the scales.
The trio, who live in Monkey Tails, hop on the scales to ensure they are the correct weight, and are rewarded with a tasty mealworm for their efforts.
See trainee keeper Harley Hunt weighing Rio on www.dzgtv.co.uk
CAPTION: Saki monkey Rio.