Diablo and Delilah are Golden Lion Tamarin monkeys at Brookfield Zoo. They live in the zoo's far west end woods, a part many visitors miss. There, they're living like their wild cousin in native Brazil- roaming without cages or nets.
"Yes they are. They have every opportunity to go anywhere they want out in this forest. Hopefully, though, they will stay within the boundaries we have selected for them," said Vince Sodaro, Lead Keeper Brookfield Zoo.
But their boundaries aren't physical they're psychological. An old cooler serves as their home -- and they don't wander very far away. The experiment has been going on for two weeks now and so far Diabo and Delilah have been learning the ropes of their new lifestyle very well.
"Kind of like basic training for them. How to get along on trees, how to get along on ropes. We do supplement them with a few additional feedings but they have every opportunity to find something to eat out here on their own," said Craig Demitros, assistant curator of primates.
Diabo and Delilah have radio transmitters around their necks just in case they do decide to take off. That way they can be tracked and brought back home.
So visitors should bring binoculars to check out Delilah and Diablo because they're not easy to see. And, they're certainly not going to come after visitors.
"Absolutely not. These creatures are very timid and shy. They're rather squirrel-like in their behavior. They're easily startled," said Sodaro.
Another big reason Diabo and Delilah won't run away: They are a couple. This cooler in the tree is their home and they will probably raise some little monkeys here.