Schroeder became director of the Zoological Society in January of 1954. He
was the Zoo's first leader with a scientific background in animal care. Dr.
Schroeder received his doctor of veterinary medicine degree from Washington
State University in 1929 and had initially been hired at the Zoo as a
veterinarian/ pathologist in 1932. But, as he often recalled, he performed
many other duties as well, such as taking photographs to sell to visitors
as postcards.
It was through Dr. Schroeder's vision and persistence that the San
Diego Zoo's sister facility, the San Diego Wild Animal Park, came into
existence and later opened to the public in 1972. As director of the Zoo
until 1972, he was also responsible for many other now well-known Zoo
attractions, including the Skyfari aerial tramway, the Children's Zoo, and
the moving sidewalk or escalator. He further increased the Zoo's commitment
to research and remodeled its hospital.
It was also during this period that the local television show
"Zoorama" was created, with its first airing in January 1955. Later
syndicated nationally, the program brought the San Diego Zoo into the homes
of millions of viewers across the nation.
Into the Present
The history of the San Diego Zoo in recent years has been one of a new
awareness of the role of zoos in our world. Under the able leadership of
new directors and members of the board of trustees, the Zoo has become
increasingly concerned with captive breeding and the conservation of
wildlife. Consequently, a number of conservation projects have been
established, both at the Zoo and Wild Animal Park as well as elsewhere
around the world. The first international conference on the role of zoos in
conservation was hosted by the San Diego Zoo in 1966, during the
celebration of the Zoo's 50th birthday. In addition, the Zoological Society
presented its first conservation awards that year.
Perhaps the most outstanding of the Zoo's conservation projects has
been the Center for Reproduction of Endangered Species (CRES). Launched in
1975 as an intensive research effort to improve the health and breeding
success of exotic animals, CRES is dedicated to its primary goal of helping
endangered species of animals reproduce and survive, both in captivity and
in the wild.
Some of the achievements CRES is most proud of have included
gratifying reproductive successes with cheetahs, Indian and southern white
rhinoceroses, and Przewalski's wild horses.
THE ANIMALS OF EURASIA
Eurasia is the largest land mass on earth, stretching halfway around
the globe from the British Isles to the Pacific Ocean, and from the Bering
Sea south to the tip of Malaysia, an area of 54 million sq km (21
million:sq -л»ХА few of its animal species, especially those in the north,
are closely related to, and in some instances are the same as, those of
North America.
Relatively recently, as earth time is measured, Eurasia was linked to
America by a land bridge which spanned what is now the Bering Straits. This
causeway existed for thousands of years during the Ice Ages, when much of
the earth's water was locked up in glaciers, thus lowering sea level.
Animals crossed back and forth between the two continents on the land
bridge, and the first human settlers in America probably arrived via this
route.
About ten thousand years ago, the latest in a series of ice ages came
to an end. The ice melted; the seas rose, and the Bering land bridge was
submerged. Animal species which had wandered west into Eurasia or east to
America were isolated from their native homelands. But because ten thousand
years is a mere eye wink in evolutionary timekeeping, very few changes have
had time to take place in these exiles. For example, the largest member of
the deer family lives in the taiga of both Eurasia and America. In Eurasia
it is called an elk, in America, a moose. But it is one and the same
animal. This is also true of another deer, the caribou, or reindeer. The
former is a wild animal of America; the latter has been domesticated for
centuries by the Lapps of northern Europe.
The Bering land bridge was probably responsible for the survival of at
least one species — the horse. This animal originated in the western
hemisphere, where it developed from a tiny, three-toed creature, to the
form very much like the one we know today. During the Ice Ages, it migrated
across the land bridge into Asia, where it thrived. In America the horse
became extinct and didn't reappear here until the Spaniards brought it back
as a domesticated animal in the 16th century.
The Spanish horses, as are all domestic breeds, were descendants of
the wild horses which migrated from America. That original breed still
exists. It is called Przewalski's horse, named for the naturalist who first
brought specimens to Europe from the grasslands of Mongolia. This is the
only true wild horse left in the world. All other so-called "wild" horses
are feral animals, that is, horses descended from domestic animals which
escaped from or were released by their owners. Przewalski's horses once
existed in large herds, but human intrusion into their habitat pushed them
farther and farther back into a harsh environment where even these tough
animals could not survive.
They were last seen in the wilderness in 1967. Fortunately breeding
groups existed in zoos and reserves. Captive propagation brought the
population up to about 700 by 1985, and four dozen Przewalski's horses have
been born at the San Diego Zoo and the San Diego Wild Animal Park. Several
of the Zoological Society's Przewalski's horses are on breeding loans to
other zoos.
The Eurasian bison, called a wisent, is closely related to the
American bison. Although never so numerous as the American member of the
species, wisent used to roam the forests which covered western Europe.
Centuries of cutting destroyed all but a small remnant of these forests and
came within 17 animals of exterminating the wisent. A captive breeding
program saved them and today a few hundred live in the Bialowieza Forest in
eastern Poland. The San Diego Zoo has produced 25 calves.
If the felling of Europe's forests meant the destruction of many wild
animal species, it worked to the advantage of others. Deer, for instance,
have thrived and live from the British Isles eastward. Red, roe and fallow
deer live in western Europe, sika deer in Japan. Pere David's deer,
formerly a native of marshy areas in central China, is extinct in the wild.
It exists only in zoos and reserves.
The hedgerows of western Europe house many small animal species. There
are foxes, rabbits, hares, badgers, ferrets, squirrels and birds. These and
other animals have adapted to life in a human-dominated environment.
Starlings and sparrows, for example, do so well that they are considered
"pest" birds. Until recently, one of Europe's largest birds, the white
stork, even nested in the smaller towns and villages. The bird was
considered a symbol of good luck, and home-owners built platforms on
rooftops for its nests. This practice is no longer common and the stork
avoids the towns.
The most regal of Eurasia's raptors is the golden eagle, and the bird
has figured in history for centuries. Its image was carried by Roman
legions as they conquered much of the continent. During the Middle Ages,
lesser members of royalty were free to use other raptors for falconry, but
the eagle was reserved for the king. Today, in more remote parts of Asia,
the golden eagle is used to hunt wild goats, gazelles, foxes, and wolves.
The bird occurs in the United States, where it is under federal protection.
It can be seen in San Diego's back country and often is observed soaring
over the San Diego Wild Animal Park.
Several other northern Eurasia predators are found in North America —
falcons, hawks and owls; mammals including wolves, wolverines and foxes. a
However, two mammalian predators are unique to I the Old World —
leopards and tigers. Leopards range i from northern Asia into Africa;
tigers live only in Asia I from Manchuria southward into India and
Malaysia. There are five races of this great cat; all of them are
endangered. The Zoo enjoys considerable success breeding and raising
Siberian tigers, of which the total world population is only about 750
individuals. More than two dozen cubs have been born and raised at the Zoo.
South of the taiga, Eurasian biomes become less clearly defined. Much
of the area is flat and treeless. In the west, where rainfall is adequate,
grass grows thickly. But deep in the continent's interior, the land becomes
a desert. Here, thousands of miles from the moderating effects of the
ocean, temperatures can climb well above 38°C (100°F) in summer, and
plummet far below freezing in winter.
Animals must make drastic adjustments to these climatic extremes. One
of the most common is migration. Herders move their domestic herds and
flocks, following the seasons, and many of the wild grazers also make
similar journeys, with predators following along.
The animals which are permanent residents have adapted to the heat,
cold and aridity of this area. The saiga, an antelope-like animal, has
nostrils pointing downward to help keep out dust. Inside each of its
nostrils the saiga has a sac which is believed to warm and moisten the air.
The Bactrian camel of Mongolia and China has adapted to its
