KEEPING ZOO ANIMALS HAPPY (Nov, 1950)
KEEPING ZOO ANIMALS HAPPY
WHAT’S the secret of gathering thousands of wild animals from every corner of the globe and getting them to live happy and contented lives in the same zoo?
Polar bears fresh from the Arctic, babirusas and gorillas from the jungle, grizzlies from the mountains and rare fennec foxes from the barren Sahara all live in different climates, eat different foods and have different habits, yet they can be made to thrive in the same menagerie.
In the past a zoo had to replenish its exhibits with new specimens continually because it seemed that animals moved far from their homes would not remain happy and healthy. Tropical animals caught cold and died during the winters and animals from the frigid zones succumbed during hot summer days. Cramped cages broke the hearts of animals accustomed to roaming for food.
But today in San Diego 3,000 animals gathered from every continent and climate are leading happy normal lives. More than 600 different species, ranging from tiny birds and snakes to gorillas and elephants, are living in the 200-acre park of the Zoological Gardens of San Diego. Rare animals that never before lived long or bred in captivity are flourishing as if they were still in their native surroundings.
Mrs. Belle Benchley, under whose management the zoo has grown to be the second largest in the United States, explains that mere food and shelter are not enough to keep any wild animal in good health. Discontent from the wrong surroundings alone may cause ill health. Putting a small tree in a bird cage may make all the difference in the world if the birds seem dopey and despondent. Mrs. Benchley and her staff try to provide each species with quarters that seem natural and comfortable. Buffalo and deer have long ranges in which to graze, the tapir and the hippopotamus have pools in which to wallow, and most of the birds are placed in cages large enough for reasonably long flights.
One of the prize exhibits consists of two giant mountain gorillas, now about twelve years old, that have flourished since they were delivered to the zoo by Martin Johnson in 1931. No gorilla has ever been born in captivity so Mrs. Benchley has to estimate their age by the fact that Ngagi, who now weighs 460 pounds, had just lost his baby teeth when he joined the zoo. That was seven years ago and as far as is known gorillas lose their baby teeth when about five years of age. His companion Mbongo, who weighed 120 pounds at the time of arrival and who has doubled in weight, lost his baby teeth a few months after arrival. Gorillas used to be one of the most difficult of all animals to keep alive in captivity, principally, Mrs. Benchley declares, because their keepers insisted on treating them either like backward children or vicious humans instead of the wild animals that they are.
“Keeping animals contented depends up-, on helping them feel secure and at home,” Mrs. Benchley says. “They obtain a sense of security from the back wall in each cage or exhibition space that keeps them from worrying about being attacked from the rear. Animals appreciate privacy, too, and enjoy enclosed spaces or caves in which they can eat and sleep in peace. We never handle an animal unless it is necessary because the excitement and fear that is aroused is apt to sicken it for days. All animals need sufficient room and an inducement to exercise if they are to remain healthy.
“Animals enjoy the company of their own kind and we try to raise each species in family groups. Some animals such as deer sometimes live in even larger groups and we let such animals run in herds.
“Of course, that sometimes means that there will be fights and that some of the animals will be injured but we have found that they remain happier if we let them work out their own self-government. There is usually one leader or bully in each cage of monkeys. We have to throw food into different parts of the monkey cage at one time to keep such a bully from getting it all.”
For the first month after a new animal arrives at the zoo, fresh from its native jungles or mountains, it lives in a special quarantine station. This is mainly so that its reaction to different foods can be noted and the right diet worked out for it. Animals from the tropics arrive during May so that for the next few months they will have the benefit of high summer temperatures. Similarly, late in September is the best arrival time for animals from the north and far south. Acclimatizing the animals requires about a year as they must adjust themselves to changes in climate and diet as well as become accustomed to the captive state. Strangely enough, Arctic animals such as polar bears and fur seals adjust themselves to the temperate climate of San Diego more easily than do apes and other animals from the tropics. Many tropical animals live in heated quarters during their first winter at the zoo.
Diet, more than anything else, adjusts an animal to its new climate. Different zoos have tried refrigerated pools, frigid rooms, and steaming tropical cages for some of their rare exhibits without much luck. The right diet does the trick much better. Animals and birds from the tropics are given more fat than they generally eat so that they can endure the colder winters, and animals from the frigid zones receive more greens and less fat.
Practically every known kind of food from milk and eggs to squab and rabbits, as well as all kinds of hay and grain make up the menagerie’s menu. The meat eaters consume 600 pounds of meat and 400 pounds of fish every day. One hundred and seventy tons of hay and 100 tons of alfalfa per year supplement the grains fed to some of the others. Ninety pounds of stale bread are on the daily bill of fare and every available kind of vegetable and fruit, strictly fresh, is also served. Red meat is not enough to keep lions and tigers in condition and they are supplied with liver, kidney, and similar meat as well. Chickens and rabbits and other small animals that are killed for feeding snakes and owls are fed whole since fur, bones, and feathers are an important part of the natural diet of these animals. Once a week the tigers and other “cats” are fasted for twenty-four hours in imitation of the occasional fast that they experience in the wilds when hunting is poor.
Even the way animals are fed is as important as providing the right food. Some monkeys won’t eat fruit unless they can peel it themselves while other monkeys have to have their fruit cut open for them. Lions and tigers want their meat in great chunks and a dark private place to which they can retire to gnaw at their food. Some birds like to scratch for their food, others want it on the trunks of trees, while still others sulk and starve themselves unless they can obtain their meals on the high swinging top branches of trees.
Another part of the job of keeping animals happy is to provide them with something to do. All of the monkeys except the gorillas are mechanically minded and like « to have balls, old tires, chains, and bells that they can take apart or play with. The gorillas prefer ropes swinging from the top of the cage that take the place of strong vines, and stumps and logs that can be rolled around. Gibbons and spider monkeys, used to traveling on the tops of trees, are provided with mazes of high trapezes so that they can swing along in any direction inside their large cages. Bears like caves for sleeping and hibernation and the wart hog likes a small cave that he can back into.
All clawed animals like to have tree trunks on which they can sharpen their claws and most birds prefer trunks with the bark still on. The cat animals, too, and the bears like. natural trees or imitation concrete trees with many branches on which to climb. The goat tribes appreciate high towers and precipices. Tall towers with steep runways and with jutting corners and ledges have been built for the goats and mountain sheep at the zoo and one of the wild mountain goats always bears its young at the top of one of the towers. The baby is able to make its way down to the ground a few hours after it is born, a feat that would be difficult for most humans.
Practically all birds and animals enjoy the rain and the keepers have learned not to shut them up when showers begin. Many of the animals also like a daily swim in a pool. Even the gorillas and tigers want an occasional bath, and pools are also provided for the bears, elephants, tapirs, swine and for some of the reptiles that like to play in the water. Fresh running water is provided in every cage and enclosure for drinking purposes. The raccoons have to have a special small pool because they like to wash every piece of food before they eat it. The gorillas wash some of their food, such as bananas and apples, but don’t wash carrots, celery, or oranges. The distinction seems to be that the primates wash only the foods having rinds that they expect to eat.
The trend in zoo architecture is to eliminate barred cages in many cases so that the wild animals can be watched more naturally by the spectators. Monkeys and apes, of course, must still be kept in cages because they are great climbers, but at San Diego you can peer directly into bear dens, and watch lions and tigers sun themselves only a few feet away, and yet remain in perfect safety. These grottoes for the bears and lions are walled on three sides and the walls arch inwardly so that the animals can’t escape. The front of each grotto is protected by a long narrow pit and in some cases a moat that is hardly apparent to the spectators and yet is wide enough to prevent the animals from leaping across.
One of the attractions of the zoo is the biggest bird cage in the world, a screened enclosure so vast that it contains trees more than 100 feet tall. The cage is 122 feet high, 210 feet long and sixty feet wide, large enough to permit long flights by the eagles and other birds it contains. This cage has enabled the zoo for the first time in history to raise man-of-war birds in captivity, since these pirates of the tropics are happy only when they can steal their food from the beaks of other birds while they are flying in the air.
Healthy animals don’t need hospitalization but when claws have to be cut, wounds dressed, or a broken limb placed in splints the animal is moved to the zoo’s modern animal hospital for treatment. Every kind of disorder can be treated as well as repairs made to mechanical injuries. The hospital equipment includes X-ray facilities, operating tables, provisions for administering anaesthetics, and compression cages in which animals may be held while the sides are squeezed together to hold them motionless while wounds are being treated.
Animals and birds normally have their babies in the spring. This leads to complications when new animals from the southern hemisphere arrive. The seasons are opposite to ours south of the equator and spring down there occurs when we are having our autumn. True to the calendar, animals fresh from the south have their babies during the fall months for the first year or so, at the time when it is spring in South America, Africa, and Australia. After that they learn to adjust themselves to the new seasons and raise their families at the proper times.