The following questions were answered by zoo nutritionist Ellen Dierenfeld, and zoo biologist Will Waddell.

What do you feed spider monkeys?
Spider monkeys eat quite a bit of fruit, as well as raw vegetables, green leaves, and primate biscuits. We usually give them a mixed bowl of bite-sized foods.

What nutrients do primates need?
Primates, guinea pigs, some birds, fruit bats, and many reptiles and amphibians need vitamin C in their diets, as they can't manufacture it themselves. Fresh green plants provide a good source of vitamin C — like kale, spinach, dandelion greens — the dark green plants, NOT lettuce, and are also good sources of protein, beta carotene, and calcium. Fruits and seeds (nuts), which these animals also eat, are imbalanced in these last nutrients, and many health problems have been created in critters that feast on fruits and nuts exclusively.

What would a capuchin monkey eat?
In nature, capuchins are rather omnivorous, and eat insects, small vertebrates, bird eggs, and plant material. Primates don't necessarily need diet diversity, but they do need proper environments, stimulation, and "toys" to develop normally, much the same as humans. Sunlight or vitamin D-3 in the diet is also essential.

What diseases can monkeys get?
Monkeys are primates, just like humans. Think about the worst sickness you could get — monkeys can get everything humans can. That's why many primate exhibits are separated from the public with glass — to cut down on germ transmission. So cover your mouth when you sneeze near monkeys!

What do gorillas eat?
Gorillas eat only plants in the wild, with lots of fiber and very little fat. We're just developing high-fiber biscuits they enjoy, and we've seen improved health with lower cholesterol problems. Our gorillas eat big green salads every day, with raw vegetables, very little fruit, high fiber biscuits, fresh browse from the trees, and no meat or eggs. Youngsters also get yogurt.

What does an orangutan eat?
An orangutan (whose name means "old man of the forest") eats a variety of plants and some animal materials. The fruits they consume often have much more fiber and less water and sugar than fruit substitutes found in zoos. In Southeast Asia, they consume leaves, buds, young twigs of trees, fruits, seeds and nuts, as well as some insects, occasional bird eggs and small animals. In the zoo, we like to feed them high-fiber primate biscuits, vegetables like carrots and yams, and a minimal amount of fruit (no more than about 15 percent of total diet), as well as branches and leaves of local trees.

What is the digestive system of the orangutan like?
I dont think that I've ever seen a diagram of the orangutans digestive system. Its gut is similar to a human's, although the colon is probably larger (more like a pig). The larger colon is needed because the foods they eat in nature have a much higher fiber content, which causes the gut to develop more haustrations (folds and complexities). With a bigger hindgut, they can harbor more bacteria to break down the plant cell walls for energy. Two main problems with zoo animals include obesity and diabetes. Orangutans typically eat fruits and leaves in nature, and very little animal matter. The leaves and fruits they consume are drier, contain less sugar, and much more fiber than our "store-bought" fruits. Some of the zoo problems may be associated with diets that are too easily digested, along with not enough exercise or activity in obtaining foods. See, they have the same problems as many humans!

What is an aye-aye and what does it eat?
The aye-aye is a very primitive primate from Madagascar. It has a very long middle finger, which it uses to tap on trees to find insects, then to dig them out for dinner. Only two facilities in the world house aye-ayes in captivity — Jersey Wildlife Preservation Trust, on the Isle of Jersey, and Duke University (SC) Primate Center. But last year I had the opportunity to work with a woman who studied their feeding habits for her doctoral thesis. During the two years she watched, they ate nuts of a certain tree, large grubs, small grubs, and a dry fungus. Seasonally, they also ate flower nectar.

Can you tell me which mammal is the smartest primate next to humans?
I suspect that most people would agree that the gorilla, orangutan, and chimpanzee are the smartest mammals next to humans. I think there are other animals that are "smart" in their own way. Heres a thought — are humans really that smart if we are destroying the places that other animals need to live?