For about 20 years, the National Zoo has allowed a pair of golden lion tamarins, a species of endangered monkeys, to roam freely during the summer so volunteers can study their behaviors and the animals may eventually be returned to the wild.
The tamarins' trouble comes from a lack of space in their natural habitat, which leads to a limited gene pool and interferes with their breeding, according to National Zoo spokeswoman Pepper Long.
The study is part of an international collaboration known as the Golden Lion Tamarin Conservation Program, which involves the Brazilian government and the National Zoo.
The monkeys, named Rio and Chrysta, are no larger than an average squirrel.
They have a home in the zoo designed to simulate their natural environment so their movements within it may be studied. Vines are substituted with ropes and food is scattered throughout their habitat so they are forced to forage as if they were in the wild.
The study of the golden lion tamarins' movement is key to their conservation because the Brazilian government plans to build "corridors" connecting rainforests so the animals have more space to allow population growth, Long said. The construction of paths of rainforest used to expand the monkeys' habitat will depend on how they typically move.
The zoo's goals include studying the animals' movements and building a diverse gene pool so they may be reintroduced to the wild once the corridors are built in the Brazilian rainforests.
The zoo's primary mission is "to protect animals by celebrating them, studying them, learning from them and, in the case of the golden lion tamarins, successfully reintroducing them into the wild," Long said. The first sign that appears on the path to the monkeys' home base cautions, "Free-Ranging Monkeys! Please hide your food and drinks, and kindly refrain from smoking."
Two volunteers, equipped with walkie-talkies, constantly observe Rio and Chrysta's behavior during their "active period," which occurs between 7 a.m. and 7 p.m. The volunteers, who declined to give their names, said the animals tend not to leave their area.
Elisa Rivera, who visited the zoo last Monday with her sister and infant daughter, felt compelled to avoid the monkeys' habitat.
"I would never jeopardize the safety of my daughter," Rivera said. However, the volunteers said after many years of being studied, the animals have proven to be harmless to humans.
On the few occasions they have wandered off to the Visitor Center or the Bird House, the monkeys have immediately returned to their own space before any human interference was needed, the volunteers said.
