When Critters get the “Munchies”

[dcwsb inline="true"]
Zoo InternQuest is a career exploration program for high school students. For more information see the Zoo InternQuest blogs. For more photos see the Zoo InternQuest Photo Journal.

On a chilly Thursday, we interns joined Jennifer Parsons, an Associate Nutritionist, at the San Diego Zoo’s food storage facilities. Since only about ten zoos in the United States have full time nutritionists and since animal nutrition is a topic I find fascinating, I was understandably excited to learn more about the topic. The job is so challenging that, as Miss Parsons said, nutritionists “kind of need to have a little encyclopedia in [their heads.]” Click the link below to read more.

A Koala, one of the 7000 animals from 800 different species that the San Diego Zoo’s three full-time nutritionists care for, snoozes under a bunch of eucalyptus leaves. These leaves, which make up the majority of the koala’s diet, are grown both on Zoo grounds and other sites around town. The Zoo is very selective about where the leaves are grown, requiring certified organic, clean sources in order to keep the animals healthy.

Miss Parsons let interns peep into one of the two giant freezers the zoo uses to store meat and fish. Her job involves a variety of challenges, including creating special diets for animals with health problems. Because good care helps many animals live much longer in the Zoo than they would in the wild and because it is usually impossible to recreate their natural diets exactly, more animals develop illnesses such as heart disease, renal problems, and diabetes than would do so in the wild.
In a nearby refrigerator, hundreds of mealworms wriggled and squirmed as Miss Parsons scooped some up to let interns take pictures. These little larvae not only look delicious (to the Zoo animals that eat them, at least) but also are quite nutritious. They contain nearly 50 percent protein and plenty of minerals.
Crickets are another kind of insect fed to animals at the Zoo. Before being fed out, though, these bugs are allowed to gorge on nutritious powder filled with calcium, vitamins and minerals to make them more healthful. Usually, crickets are high in phosphorous and low in calcium – the opposite of what most animals need – but this powder amends that problem. According to Miss Parsons, the Zoo’s polar bears are especially fond of these bugs and regularly eat them as low calorie snacks.
These containers are filled with night-crawlers, another delicacy for many of the Zoo’s furry and feathery residents. Although the labels proclaim that “worms work best dipped in gravy,” apparently the animals and birds eat them just as happily without toppings.
This rather intimidating machine is a band saw kept in one of the Zoo’s huge forage warehouses. Zoo food preparers use it to cut large bones into smaller chunks. Most of the carnivorous animals at the zoo get soft food, so keepers give them bones to strengthen and clean their teeth. The polar bears also get carrots, which act like giant, tasty toothbrushes.
Miss Parsons showed interns one of the Zoo’s large barns filled with different types of hay for the resident hoof-stock. Contrary to popular belief, cows and other ruminants do not have four separate stomachs – rather they have three extra chambers before the true stomach in which to ferment their food with cellulose-digesting bacteria. This form of digestion limits the size of a ruminating animal because it is a rather time-consuming way to get energy. The animal cannot be so large that the process takes too long or so small that they lose too much energy keeping themselves warm. The Royal antelope, a creature about the size of a chihuahua, is the smallest known ruminant, and the giraffe is the largest.
Because the fresh foods available to the Zoo often lack certain nutrients animals normally eat in their natural environments, nearly all the Zoo animals’ diets are supplemented with specially formulated pellets. Companies like Purina and nutritionists work together to develop these diets by using their knowledge of human nutrition and similar species’ diets as well as by trial and error. Usually physical signs such as scaly skin and coat problems will be the first signs of a deficiency which may then be corrected. Unfortunately, detecting deficiencies in zinc, copper, and other minerals which are stored in the liver cannot be detected easily and may require a biopsy.
The San Diego Zoo also keeps a gigantic fridge stocked with produce to feed the animals. Unfortunately, the varieties of fruit available, like those in a grocery store, have much more sugar and less fiber than fruits in the wild. For fruit-eating animals like binturongs, this can lead to diabetes, but Miss Parsons and other nutritionists at the Zoo are looking into the problem in an attempt to fix it.
One shelf in the refrigerator was piled high with apples and carrots. All the food at the zoo is “people quality.” Much of it looked so tasty that several interns were wishing for a taste, but not even the keepers are supposed to eat the food designated for the animals.


Rachel, Photo Journalist Team