Life is fairly quiet at the Duke Lemur Center at this time of year. The Duke students, who would normally be conducting observations or doing non-invasive research, are preparing for or taking exams. The more than 30 Duke affiliated researchers (All our research is non-invasive) are preparing or grading exams. So from the lemurs' point of view, there are not only fewer people, there is less activity than usual.
Now, lemurs and their fellow prosimian primates, lorises and galagos, are intelligent. In fact, research being done here is showing that they are more intelligent and more socially oriented than was previously understood. That means they can get bored. So, 365 days of the year our dedicated Primate Technicians make certain that their lemurs' lives are interesting.
One way the technicians enrich the lemurs' lives is through a training program. First, all the techs completed a course by Meg Dye in animal training based on the science of operant conditioning . They use positive reinforcement to train the lemurs to allow themselves to be touched by the trainer, to sit on a scale, to enter a kennel, to move to a certain certain spot - a set of behaviors that just seem like play to the lemurs, but can serve a purpose when needed.
For instance, Pia, a Coquerel's sifaka, is very pregnant. So her technician, Sam, is training Pia to allow Sam to touch her belly. That way Pia will be less stressed and more comfortable after her infant has arrived and Sam needs to approach Pia and lift the infant from her stomach to be weighed. Sam will give a familiar command and Pia will know that it is safe for Sam to touch her belly and that she will receive a tasty treat.
Each appropriate response from the lemurs merits a treat, like a raisin or a nut - depending on what is a treat to that animal. The techs wear a special belt that has a treat pouch attached. When the animal responds appropriately, the techs click a clicker. That sound tells the lemurs that a treat is coming. That way if there needs to be a brief wait between the behavior and the reward, the lemur still knows it's coming. I think of it as that space between the timer dinging on my stove at home and a warm cookie making into its way into my mouth.
The techs also make sure that they end each session with behaviors that are sure to get a positive response from the animal. That always brings the Jackpot - a small handful of treats.
As I watched the training, it certainly looked like both trainers and lemurs were happily engaged. I know as Sarah and David were training sifaka in one cage, the ringed-tails in the next cage were getting as close to the sifaka cage as they could, jumping excitedly and making a sound that Sarah described as a whine. It was easy to picture a young child watching another play with a special adult and calling, "My turn! My turn!"