Zoo

A

2

Exhibit Design

When developing the way animals are housed and exhibited, zoo planners make the safety of animals and humans the highest priority. Getting close to animals is part of the fun of visiting a zoo, but from a design perspective, it has to be managed with care. Exhibits that allow visitors to come too close to a wild animal may cause the animal to become alarmed or act aggressively. In nature, most animals keep a safe distance between themselves and potential danger, and their instincts tell them to flee the moment this safety zone is breached. In general, zoo animals are much more tolerant of being approached than their wild counterparts, particularly if they have been born in captivity. But zoo animals also have their limits, and zoo planners keep these in mind when they design zoo exhibits. In animal parks visitors can closely observe animals in their “wild” habitat from the safety of monorails or railroad trams, a method that protects animals and visitors alike.

For zoo planners, making animals easy to view is just one aspect of design. Equally important is providing a stimulating environment for the animals themselves. Animal needs vary enormously. Snakes, for example, thrive with few distractions apart from an occasional meal. Other animals, such as pigs, monkeys, and bears, need complex surroundings that give them a chance to play, explore, and forage for food. If they cannot perform these activities, they begin to behave in an abnormal way, often grooming themselves for hours on end or pacing around in the same limited part of their quarters. Repeated actions such as these—known as stereotyped behaviors—are a sign of mental deterioration.

Zookeepers provide mammals with stimulation in many ways. Primates enjoy playing with toys just as much as humans do, and many animals benefit from having to search for their food. In the past, zoo animals were also trained to perform for food rewards, a practice that still continues at some aquariums that keep whales, dolphins, and porpoises. However, zookeepers today are generally cautious about teaching animals to perform tricks for the simple purpose of entertainment unless it can be shown that the animals are benefiting from the experience. At the Woodland Park Zoo in Seattle, Washington, for example, zoo experts train elephants to move logs and perform other work. Visitors may be entertained watching elephants pick up huge logs with their trunks, but zookeepers believe that the training and work involved in these tasks also provide the elephants with enjoyable intellectual activity, which keeps the animals happy.

In zoo design, animals that have precise requirements pose some of the most interesting challenges. Leafcutter ants, for example, snip pieces of leaves from the treetops and then carry them to a large nest underground. In the nest the ants use the leaf pieces to grow a fungus that provides them with their food. To successfully raise these insects, zookeepers must provide the ants with acceptable food plants, a suitable nest site, and climatic conditions in which the fungus can thrive.

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Zookeepers must also meet the temperature requirements of a variety of zoo animals. At some zoos, the climate is mild enough for most tropical species to stay outside year round, but other zoos require heated areas to keep resting animals warm. In some parts of the world, the winter cold is so severe that animals must seek shelter indoors. At the Metropolitan Toronto Zoo in Canada, zebras and white rhinos live outdoors during the summer, but in winter—when temperatures can drop to –30°C (-20°F)—these animals have to spend several months indoors. Polar bears have the opposite problem—they have such good insulation that they easily overheat. When designing zoos in warm climates, zoo planners must devise enclosures for polar bears that maintain icy Arctic temperatures.

B

Animal Care

Zookeepers work with a wide range of animals, but they often specialize in the care of particular animal groups. Some animals quickly become comfortable with their keeper’s presence in or near their enclosure and grow accustomed to their keeper's routine. In turn, the keeper develops a detailed knowledge of individual animals, their health-care needs, and the way they normally behave. Zookeepers are usually the first to notice any changes in behavior or eating habits that might be an indication that an animal is ill or injured.

Over the years, some animals become so accustomed to their keepers that the animals act very much like household pets. However, zookeepers constantly bear in mind that the animals in their care are not domesticated. This is particularly important when animals are under unusual stress—for example if they have recently been moved, if other animals have just joined their group, or if they have newly born young. In these conditions, keepers have to be careful not to trigger defensive behavior in animals that could place the keeper or other animals in danger.

C

Diet

Keeping zoo animals properly nourished involves many people. Zookeepers give animals their food rations, but veterinarians and nutritionists work behind the scenes to ensure that each animal receives a balanced diet. Zoo kitchens must stock a wide variety of meat, fish, insects, grains, and plants to meet the needs of different animals. Kitchen workers chop and grind food, add vitamin supplements, and sometimes cook food to make it appetizing and nutritious for each animal. Some animals, such as deer, will thrive on plant matter of almost any kind, while many carnivorous mammals and birds will succeed on almost any kind of meat.

Other animals have specific dietary requirements that can be harder to match. For example, in the wild, the giant anteater and aardwolf feed exclusively on termites and ants—foods difficult for a zoo to supply in large quantities. For these animals, a substitute diet based on cooked egg and finely ground meat is used instead. Other insect-eaters, such as chameleons, present even greater problems because they will only eat insects that move. To feed them, zoos often have their own insect-breeding units, where they raise crickets, beetles, and flies on an almost industrial scale.

If zoo animals receive too much food, they can easily become overweight. Apes are particularly prone to this problem. The largest zoo gorilla was a male that weighed 290 kg (630 lb), which is about 60 percent more than the weight of an average male in the wild. This gorilla lived in the San Diego Zoo in the 1930s. Since that time, overweight zoo animals have become rarer. This is partly because zoo animals now are housed in enclosures that permit them to exercise more, and partly because zookeepers have a better understanding of animal nutrition requirements.

D

Medical Care

If zoo animals become ill, veterinarians are on hand to diagnose and treat the problem. Veterinary care may include dental work, such as removing teeth or abscesses; vaccinating animals to protect them from infectious disease; and managing captive-breeding programs and supervising in the birth of new animals. Veterinarians also perform major internal operations. When the patient is as large as a bear or an elephant, surgery calls for considerable expertise on the part of the veterinarian and the medical support staff to properly anesthetize the animal.

The effectiveness of attentive medical care—and of zoo care in general—is reflected in animal life spans. Captive animals generally have a longer average life span than do animals in the wild. Captive orangutans have been known to live into their late 50s, whereas wild orangutans live to around 30 to 40 years of age. Captive elephants have lived into their late 70s, but their wild counterparts generally do not live beyond the age of 60.

III

Importance of Zoos

Zoos are important for a number of reasons. Zoos offer a variety of educational opportunities that teach about the behavior and natural history of zoo animals and their counterparts in the wild. Zoo scientists participate in programs that bring animals from different zoos together to breed; in addition they work to protect animal habitats in the wild and they conduct research that advances knowledge of animal biology.

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