Training at Primate Forest

Here at Primate Forest (like the rest of the zoo), we use positive reinforcement training when working with the gibbons, lemurs, and monkeys. Positive reinforcement training involves rewarding an animal after it displays a desired behavior. The purpose of this training is so that we can better take care of the animals. We have trained most of the animals in Primate Forest to present basic body parts, such as hand, foot, and open their mouths. Some of them are also ultrasound trained so we can monitor pregnancies and possible heart conditions. Everyone is trained to voluntarily go into a small enclosure (for injections), and to sit on the scale for weights.

With a smaller primate, such as these, we use very small rewards. For example, when training with polar bears, the keeper might offer an entire fish. However, we cut our treats up very small so that the animals don’t fill up quickly and will still want to train. We will cut up a grape into 8 pieces or a shelled peanut into quarters.

When training with monkeys and apes, the keepers are on the other side of the mesh (caging) from the animal. We never put our fingers or hands inside the mesh with the animal. Training a new behavior with an animal can take 5 minutes or 5 years. It all depends on the animal. Sometimes the light bulb just goes off in the animal’s head when he/she understands what the trainer is asking. The trainer always needs to be prepared for the next step.

Below are some photos of different behaviors that we train.




Ashes, our female langur, having an ultrasound performed during pregnancy.


Batu, our male gibbon, presenting hand.


Cagn, a male swamp monkey, showing mouth.


Sefu, our male Colobus monkey, being closed into the squeeze cage.


Hue, our female gibbon, presenting foot.


Hue, our female gibbon, presenting hand.


Fanta, a female lemur, having an ultrasound performed during pregnancy. The female lemurs are the only primates that Zoo staff come into the enclosure with and only for ultrasound training.


Tilly, our female swamp monkey, being ultrasound trained. 

Photos by Beth Posta