Mammals and Humans: Mammals in Zoos
Mammals and Humans: Mammals in Zoos
Mammals and humans: Mammals in zoos
A brief history
Evidence from cave wall drawings suggests that wild mammals were kept in the company of humans as early as the Stone Age. In fact, this was probably the beginning of animal domestication. By 2500 b.c. Egyptian kings were keeping antelopes for amusement and to impress foreign visitors. Only ruling classes could afford to keep and care for exotic mammals. Queen Hatshepsut of Egypt could be credited with organizing the first mixed collection of exotic mammals. In approximately 1500 b.c., she sent collectors to Somaliland. They imported greyhounds, monkeys, leopards, cattle, and the first giraffe into captivity. In 1000 b.c., Emperor Wu Wang of China assembled the first zoological park. This was a sophisticated 15,000 acre (6,070 ha) Ling-Yu or "Garden of Intelligence." It included tigers, rhinos, and rare giant pandas. Between 1000 and 400 b.c., many small zoos were created in north Africa, India, and China and domestication of mammals had become an art. These collections were mostly symbols of power and wealth, definitely not for public enjoyment. By 400 b.c. the ancient Greeks established a zoological garden in most if not all Greek cities. They used their collections for serious scientific study. Only students and scholars were allowed to visit these collections. It was at this time that Aristotle wrote The History of Animals. In this encyclopedia, he described hundreds of species of exotic vertebrates from these collections.
The Romans were perhaps the first to open exotic mammal collections to the public at large. From about 100 b.c.to a.d. 600 the Romans used these collections for scholarly study but they also used many of these animals for entertainment. Much of the entertainment consisted of cruel and bloody spectacles in public arenas, with large carnivores attacking or being attacked by men as well as other mammals. Often these were slow, agonizing and gruesome battles to the death. With the fall of the Roman Empire zoos went into a decline. Most exotic mammal collections consisted of small private menageries and traveling exhibitions.
By a.d. 1400 global exploration sparked public interest in zoos once again, with strange creatures from the New World. During this time, Hernando Cortes visited the zoo of Montezuma, chief of the Aztecs. It was a huge collection and employed over 300 zookeepers. Over the next few hundred years many European zoos opened and the collections grew larger. Most of these collections consisted of individual specimens of as many species of mammals as possible. The animals were from many different countries and represented many continents. They were often called postage stamp collections. They were open to the public and attracted many visitors. Although they have been renovated and have updated their policies, some of these zoos are still open today. The oldest is the Schonbrunn Zoo in Vienna, Austria. It was built in 1752 by Emperor Franz Josef for his wife. It opened to the public in 1765. Others that still exist are the Madrid Zoo in Spain, which opened in 1775 and the Jardin des Plantes collection in Paris which opened in 1793. For comparison, the oldest zoos in the United States are the Philadelphia Zoo, which opened in 1874; the Central Park Zoo in New York, which opened in 1862; the Lincoln Park Zoo in Chicago, which opened in 1868; and the Cincinnati Zoo, which opened in 1875.
Why do we keep mammals in zoos?
Zoos have been popular for centuries and this trend continues today. In an urban setting, a zoological park offers a rare opportunity for visitors to view and learn about exotic mammals. This is the only type of opportunity many people have in their lifetime to see living specimens in person. Many of these mammals would be difficult and costly to see in the wild.
The goals of many zoos are the same. Usually they involve entertainment and education for the community they serve. Conservation and scientific research have also become major concerns for modern zoological parks. In an annual survey, the American Zoo and Aquarium Association reported that almost 135 million people visited 194 member facilities in 2001. By comparison, this attendance is greater than all professional sporting events combined in the United States for 2001.
Entertainment is a major goal for every public zoo. These attendance numbers indicate that indeed zoos are fun to visit. There are many theories as to why people enjoy zoos. It could be that current human cultures feel isolated from nature and observing exotic wildlife in zoos bridges a primal connectio and meets our psychological needs. Mammals are certainly interesting to watch and their exotic shapes and colors appeal to our artistic nature. The whimsical behavior of primates or the grace and power of elephants, appeal to visitors of all age groups.
Perhaps the greatest service a zoo offers to the community is education. Most zoos have programs that teach basic zoology, animal behavior, geography, and natural history. The classroom setting sometimes involves safaris, campouts, scavenger hunts, and participation in animal care. Usually students have the opportunity to observe, interact with, and often touch exotic mammals about which they are learning. Another unique educational and emotional experience is outreach programs that target audiences unable to physically visit the zoo. Examples include the transport of education animals and staff to audiences in nursing homes or hospitals. Increasingly important are programs teaching responsible use of habitat and conservation of natural resources. These programs often target younger audiences, in an effort to sustain the long-term quality of life for all life forms.
Zoological parks are becoming important conservation organizations. They contain a large resource base in both staff training and fund raising. Thousands of staff members employed by zoos participate in numerous in situ and ex situ conservation projects worldwide. Some of these projects have resulted in saving wild populations of mammals from certain extinction. Good examples of this are the golden lion tamarin (Leontopithecus rosalia) and Arabian oryx (Oryx leucoryx) programs. Both wild populations lacked enough animals for long term survival. A consortium of zoos working together moved and released captive born animals back into their historical ranges in hopes of re-establishing wild populations. Both of these re-introductions have succeeded and these now wild populations continue to reproduce and their numbers are increasing.
Zoos are often called "living laboratories"; this term reinforces the fact that animal observations and experiments in captivity can be very valuable. In fact, most of our knowledge of mammals has come from captive studies. For instance, black-footed ferrets (Mustela nigripes), extinct in the wild, are being re-introduced through artificial insemination. The oryx have also recently been poached to near extinction again and their numbers are just starting to increase in the wild. Also, it is often more practical, easier to control external factors, and more scientifically useful to study mammals in captivity. In an effort to encourage scientific study in zoological parks and provide funding for these programs, the American Zoo and Aquarium Association and Disney's Animal Kingdom have established the Conservation Endowment Fund. It pays for many conservation and research studies in captivity and in the wild each year. The Zoological Society of London in the United Kingdom has supported research since the late nineteenth century.
Exhibit design concepts
Early zoos consisted of numerous animals exhibited in small cages made of concrete or wood with metal bars for security. These were usually large charismatic mammals exhibited mainly for shock value. While a few zoos remain with this type of exhibit design, the majority of modern zoo exhibits are one of two types. A third philosophy is included because it could represent the future of mammal exhibits in zoological gardens.
The Hagenbeck concept
Carl Hagenbeck was an animal entrepreneur. He supplied animals to zoos and was also an animal trainer. He pioneered many display and exhibit techniques. Hagenbeck initially gained his reputation by exhibiting people and animals in traveling exhibits. On October 6, 1878 over 62,000 people visited the Berlin Zoo to see his traveling exhibit of Nubians from the Sudan, Laplanders, Eskimos, Kalmucks, Tierra del Fuego natives, and Buddhist priests. There were also elephants, camels, giraffes, and rhinos, but it was the people who were most popular. These human zoos made Hagenbeck a fortune. In 1900 he bought a potato farm on which he wanted to build a wild animal park. Hagenbeck is credited as being the inventor of the cage without bars. He put his animals in moated enclosures. The enclosures were planted with trees and shrubs and decorated with artificial rockwork which was very pleasing to the visitor and gave the illusion that the animals were free-ranging. Their captivity was well hidden. Hagenbeck was a master at the placement of moats and hedges to create an exhibit illusion that placed predator and prey together. He was not that concerned with scientific study or educating the audience, his priorities were aesthetics and beauty. These exhibits showcased large mammals with a geographic theme. Hagenbeck's concepts are still used in exhibit design today.
This philosophy was an attempt to involve or place the visitor in a naturalistic backdrop for a specific theme. These types of exhibits are often characterized by paths that wind through areas built to resemble natural habitat. Small mammals and birds are sometimes free-ranging in the entire exhibit, including public areas. Species of similar geographic origin and habitat are mixed in the exhibit, interacting with one another if they peacefully cohabitate. Larger mammals are housed within the same space, but for safety and function are enclosed within the exhibits with visually hidden barriers. Therefore, some of Hagenbeck's techniques are used in immersion exhibits. The primary purpose of this exhibit is to give the visitor an appreciation of an animal's natural habitat and educate them on the natural history and need for conservation of that habitat. One of the first good examples in the 1970s was the gorilla exhibit at Woodland Park Zoo in Seattle; more recent examples of this technique can be found in the Congo exhibit at the Bronx Zoo and the Amazonia exhibit at the National Zoo.
This technique is beginning to attract interest. The basic idea is to create exhibits that explain, elucidate, and exemplify the interconnectedness of life. More specifically, it is the idea of putting humans and our biology in the context of the rest of life. Robinson (1996) describes this technique as emphasizing "the complex specializations in a host of dependencies, interdependencies and interactions with invertebrates, plants, protozoa, bacteria, viruses and so on to which mammals have evolved." He further states "it is time to end the isolationism of simply exhibiting mammals against a naturalistic backdrop."
Management of captive mammal populations
Why manage zoo populations?
Gone are the days of extensive collecting expeditions to replace mammals that have died during transport or exhibition. Zoos must now manage their captive populations to the fullest. It is no longer ecologically responsible or ethical to capture wild mammals for the sole purpose of entertainment. In fact in 1992, 82% of the worldwide mammal population living in zoological parks was born in captivity, according to data collected in 2002 by the International Species Information System (ISIS).
When compared to wild mammal populations, most captive populations are very small. Small populations tend to be
biologically unstable and their long-term survival is unlikely if events occur at random. Genetically only one-half or 50% of a mammal's alleles are passed to its offspring. Alleles are mutable genes that are responsible for inheritable traits. Therefore, genetic diversity is reduced by 50% with each generation. In other words, the relatedness or mean-kinship of these individuals increases by 50% with each generation. This increase in relatedness also increases the chance that alleles that produce a fatal birth defect or reduced survivability will be expressed. These are often called lethal genes. Demographic factors also influence the long term survival of small populations. If an excessively disproportionate number of females or males occurs in a population, only a limited number of animals will be represented in the population. This will result in a reduction of genetic diversity and increased mean kinship. This may eventually cause a small population to crash without the addition of new founders (genetically unrepresented animals in the population). Therefore, a population with a sex ratio that is nearly equal has a better long-term chance for survival. Age distribution in a small population is also very important. If there is an excessively disproportionate number of older post-reproductive or younger prereproductive mammals in a population, reproduction will intensify in a single cycle and decline in a single cycle. Without the addition of new founders, this will also reduce genetic diversity and cause a small population to crash.
Frankham (1986) and Foose (1986) very eloquently document two extreme reasons for managing captive zoo populations. Individuals are either intentionally selected to be well adapted to captive environments, or they are managed to preserve genetic diversity.
Animal record keeping is the foundation of captive animal management. Zoo professionals depend on detailed direction from animal records. Mammals with missing or unknown ancestry or other life history information are of very limited use in long term management strategies. The International Species Information System (ISIS), first developed in 1973, collects animal data from over 560 institutions in 72 countries on 6 continents and stores them in a computerized database. These data are kept by a computerized program called ARKS (Animal Record Keeping System). Much of the data are entered into a computer software program called SPARKS (Small Population Analysis and Record Keeping System) by a studbook keeper, in order to produce a studbook. A studbook is an inventory of the life history and ancestry of an animal and SPARKS can perform mathematical analyses of studbook data. From SPARKS one can get age class and sex class graphs as well as survivorship and mortality data for a population. It can also generate many useful reproductive
analyses. In order to formulate a population management plan, SPARKS data are exported to a software program called PM 2000. This is a powerful computer program that can generate, among other things, target population size, generation time, growth rate, and current percent of genetic diversity. It also allows the user to build preferred breeding pair calculations, so recommendations can be made by the population manager.
Techniques for small population management
Incorporating profound knowledge and documentation of genetics and principles of population biology, Ballou and Foose (1996) describe specific guidelines for efficient demographic and genetic management of small populations. These guidelines are used extensively by zoological gardens in an attempt to achieve long-term survival of small populations. Their basic techniques are summarized here.
The long-term survival of a small population depends upon obtaining a sufficient number of founders to maximize allelic diversity and heterozygosity. The goal here is to obtain enough unrepresented animals to build a population that will represent a cross-section of the genotype and phenotype of the source population. Unfortunately, one cannot predict the quality of the sample because it cannot immediately be measured. Founder numbers are considered adequate for effectively sampling allelic diversity based on the most likely allele distributions. Genetic variation over the range of the source population should also be considered, with between 25 and 50 founders considered sufficient in most cases.
reach carrying capacity
Carrying capacity in zoos is the entire number of spaces available for a particular species among all program participants. In order to maximize genetic efficiency the population size should be increased as rapidly as possible in order to meet the carrying capacity. Genetic diversity is lost when growth rates are slow, because the chances of all animals in that population successfully reproducing and being represented in the first generation decreases with time.
stabilize the population
The population should be stabilized once it is near the carrying capacity. The current population size and growth rate are used to determine the proximity to carrying capacity and the population is stabilized by regulating birth control. Birth control of mammals in zoos is achieved both biologically and by the physical separation of animals.
extend generation length
Mean generation length is defined as the average age at which the females in a population produce offspring. Since genetic diversity is lost with each successive generation, extending the generation length reduces the degree of diversity lost in a small population over a given number of years. In other words, if the females in a population do not breed until later in life the loss of genetic diversity is delayed. Risk is incurred with this strategy since the animal's reproductive potential may be lost with time, due to age related fertility problems, health problems, and accidental injury or death.
adjust founder lineages
In order to maximize the genetic diversity and survivability of a captive mammal population the representation of founder lineages should be as proportional as possible to the distribution of founder alleles surviving in that living population. Initially in a captive population some animals will reproduce well and be highly represented genetically while others will not. Therefore, the population will not be evenly represented genetically. In order to compensate for this, preferential breeding pairs should be formed. Descendants of underrepresented founders should be preferentially bred and the reproduction of overrepresented animals should be limited.
reduce the representation of extreme traits
Reproduction should be limited in animals that produce traits that are not typical or that would offer a selective disdvantage to survival in the natural environment. Albinism is an example of such a trait.
subdivide the population and regulate gene flow
Division of a large captive population into geographically isolated subunits offers some advantages. The exchange of animals as well as gametes between these subunits should be regulated. This method offers increased protection to th population from communicable diseases and natural disasters such as fire, earthquake, tornado, and hurricanes. Also, isolated subunits of the population will be exposed to a wider range of selective pressures. This offers the advantage of a slowed reduction of genetic diversity.
introduce new founders
The addition of new founders should, in theory, increase genetic diversity. If a program can be devised to exchange wild caught animals for captive born ones, this can sustain a population. However, great care must be taken to eliminate the possibility of disease transfer between the populations.
incorporate reproductive technology
Emerging advances in reproductive technology can be used to increase genetic diversity and sustain a captive population. Genetic material such as semen, ova, embryos, and tissues can be stored and used at a latter date. This can increase the chances of a genetically underrepresented animal being utilized in a population. It can also increase the practical aspect of introducing new founders from wild populations. It is much easier and safer to move an animal's gametes rather than to physically transfer the entire animal.
Types of populations to manage
Frankham (1986) documents four types of captive populations of interest to zoos. They are summarized in the following groups:
common display species
The goal for these species is to selectively breed for traits adapted to captivity in an effort to establish a tractable, easily managed population. This could include animals that are docile and do not stress easily.
endangered species in captivity for long term conservation
The goal for these species is long-term maintenance of a viable population and the preservation of genetic diversity. Species of this designation require extensive genetic planning and captive management.
The North American gorilla population is one example. In 2002 there were 361 animals in that population, of the 171 potential founders, 111 are represented by living descendants. The population is doing very well, in fact 99% of genetic diversity has been retained.
endangered species being propagated for release into the wild
Reproduction for these species should be maximized for rapid population growth. Also, the captive environment should be as similar as possible to the natural environment in which the species is designated for release. External disruption should be held to an absolute minimum.
The golden lion tamarin population is a classic example. This captive population has been overseen by an international committee since 1981. Nearly all of these animals are owned by the Brazilian government. In 1990, the government of
Brazil gave the committee jurisdiction over the management of both the wild and captive populations. Therefore, this committee establishes policy for and manages the wild and captive populations of golden lion tamarins by making recommendations to the Brazilian government. The committee has no implementation authority but the government tends to accept its recommendations. As a result, the captive population supplements the survival of the wild population through reintroduction and management policy.
rare species not capable of self-sustaining reproduction in captivity
Intensive efforts should be made with these species to develop successful husbandry and propagation techniques in order to achieve self-sustaining populations. When this is accomplished, genetic diversity should be maximized in the captive population.
There are great advances being made in exotic mammal husbandry as of this writing, but much work is still needed. The reproduction and birth of captive elephants is becoming a major priority. Both the African (Loxodonta africana) and the Asian (Elephas maximus) populations are aging and without more success both captive populations could be in trouble. Efforts are currently underway by numerous institutions to produce captive born animals. The silky anteater (Cyclopes didactylus) is another animal that does poorly in captivity. The average life span in captivity is approximately thirty days. Their has never been a silky anteater born in captivity. The wild caught animals usually arrive very weak, dehydrated, malnourished, and heavily parasitized. Also, it is unclear if diets used for other species of anteaters in captivity are sufficient for silky anteaters.
Population management programs
Zoos worldwide have intensive conservation programs for mammals. Although the names and acronyms vary by the geographic region of zoo associations, their functions are very much the same. In North America, that plan is called the Species Survival Plan (SSP), a copyright name and program implemented in 1981 by the American Zoo and Aquarium Association (AZA). The Species Survival Plan is defined as a cooperative breeding and conservation program designed to maintain a genetically viable and demographically stable population of a species in captivity and to organize zoo and aquarium-based efforts to preserve the species in captivity and in natural habitats. SSPs participate in a variety of other cooperative conservation activities, such as research, public education, reintroduction, and field projects. Currently, 108 SSPs covering 159 individual species are administered by the AZA.
Most SSP species are endangered or threatened in the wild, or "flagship species." These are well known animals that arouse strong feelings in the public for their protection and that of their habitat. For an animal to have an SSP there must be qualified professionals with time to dedicate to conservation. Each SSP has a coordinator and management committee. They use tools such as population management, scientific research, education, and reintroduction to formulate a master plan. This plan outlines the goals of the program, based on what is most appropriate and attainable based on the current captive population.
No day at the zoo is the same as the previous; each day brings new events and challenges. A rigid work schedule will not survive. Disruptions and chaos are inevitable, requiring flexibility and an open mind. The management of zoo business and animal husbandry is in itself constantly evolving. Internal and external ideas from both local and global political groups, scientists, the general public, and environmental emergencies interact and contribute to change, while the health and biological status of animals determines the overall degree of success.
Basic needs of mammals
The basic needs of a mammal are food and shelter. A zookeeper's primary responsibility is to satisfy these basic needs. However, their duties are usually much more complex, and with their daily responsibilities, a profound bond between human and the other mammal occurs. Early diagnosis of health problems in the zoo population can often be done by simply paying close attention to condition of the skin. The skin should be free of rough areas or exposed tissue. The fur should also be somewhat silky and shiny rather than dry and dull in appearance. The health maintenance of elephants and rhinos is one example. The skin of an elephant or rhinoceros is a good indicator of their overall health. It should be free of wounds and have a firm condition, a loose skin texture can be indicative of serious health problems. These animals are also very susceptible to foot problems. This is due to the fact that they do not walk as much in captivity as they do in the wild. Zookeepers provide all required health maintenance while also concerning themselves with the following subjects.
In addition to physical needs, a captive mammal has psychological needs that must be satisfied. "Enrichment" means the application of environmental stimuli in an attempt to create
psychological and physiological events that improve the overall quality of life of an animal in captivity. Enrichment helps to overcome stereotypical and undesirable behavior, as well as encourages mental and physical exercise in captive mammals. It usually involves adding novel items to an animal enclosure or providing visual or olfactory cues to a novel item. The desired behavior is curiosity or investigation, which results in mental and physical stimulation or exercise. Zookeepers benefit from developing enrichment programs for the same reasons. They stimulate themselves to rethink and reduce the stagnancy of routines. In some facilities, visitors participate in enrichment as well. Many institutions have "enrichment days" in which the public participates in making enrichment items. The safety and suitability of each item for a specific animal must always be the primary concern. For example, the Minnesota Zoo uses fir trees as enrichment tool. The animals love to investigate and move around them, and tear branches apart. Snowmen are also a popular enrichment item with many of the animals at this zoo. The bison love to bash theirs, but the gibbons aren't really sure what to do when snow shows up in their enclosure.
The types of enrichment and the applications are limitless. Some groups of mammals have been documented to have specific preferences. For example, exotic cats in captivity are drawn to spices such as cinnamon, nutmeg, and paprika sprinkled in their enclosures. Perfume sprayed on surfaces in their enclosure also arouses their curiosity and excitement. For other mammals, cardboard boxes and objects that they can roll are enjoyed. Enrichment can be used to elicit "natural" behaviors in captivity as well as improve overall physical health through exercise. Food is also frequently used as an enrichment tool because it solicits the natural hunting and foraging behaviors of animals. Food with interesting textures or new flavors, and food that is hidden in hard to reach places, all make good enrichment items. Many animals love "popsicles," blocks of ice with food or bone inside. One of the Minnesota Zoo tigers is reported to put her popsicles into the tiger pool to make the ice melt faster.
Most facilities employ staff veterinarians who specialize in exotic animal medicine. Zoological medicine has been identified as a distinct and identifiable specialty of veterinary medicine on the basis of academic programs in colleges of veterinary medicine in the United States from the 1960s. In 1972, the National Academy of Science committee on Veterinary Medical Research and Education first documented the need for veterinarians specially trained to manage the health of zoo animals. It is typical for each mammal within a zoo population to receive a routine health exam at least once a year if they have no signs of illness. Care is provided as often as needed if health problems are suspected. Routine physicals usually involve blood serum chemistry screening profiles, a complete red blood cell and white blood cell count, x rays,
and dental cleanings. Appropriate vaccinations against life-threatening diseases are also given. A fecal analysis to check for the presence of parasites is usually performed every three months on each mammal in a zoo collection. In the event of a serious illness, many zoos have access to and perform the same advanced procedures on captive mammals as a human would being treated by a surgeon or other specialist. Veterinarians depend on the input of zookeepers for evaluating when an animal is sick and what would be the least stressful mode of treatment.
Training is another technique that zookeepers often use to improve the quality of care of mammals in captivity. Although the term "training" probably conjures up images of tigers jumping through hoops of fire or elephants in ornate dress standing on their heads, training for the purpose of management in modern zoological parks has a very different purpose. When an animal caregiver needs to get very close to, touch, or otherwise interact with a mammal, that specimen must be conditioned to allow their presence. Target training is the method by which this conditioning behavior is learned. It can be a simple or complex program depending on the species and the training goal.
The training of mammals in zoos usually involves two techniques. One is the theory of shaping. This involves the immediate reinforcement of a desired behavior with some sort of reward to the animal. When a mammal receives positive reinforcement for a particular behavior, it repeats that behavior. Shaping several small behaviors initially and then forming them into a series, is the method by which a training program is built. A second method often used is target training. In the simplest form a target is used to focus the animal's attention. The target is often a colorful ball on a stick or a colorful card. When an animal touches the target or performs the behavior that is required by the trainer, a bridge occurs. The bridge is a form of non-verbal communication and feedback between trainer and animal. The bridge is usually a whistle, clicker, or other device that makes a sound that is audible to the animal being trained. The bridge is often accompanied by a reward. Therefore, when the animal hears the bridge it knows it has performed the correct behavior and may get a reward. Training in zoos is very helpful for captive management. An animal can be trained to position in a specified area or hold a stationary position. This can allow a zookeeper or veterinarian to perform a physical exam, and collect blood, as well as other medical procedures without the danger of anesthesia.
Keeping wild mammals in captivity has been a controversial issue since the industrial revolution created more time for such interests. As late as the 1970s, most zoos kept species that were easy to acquire at the time, in substandard conditions. Apes, monkeys, tigers, and bears were kept in concrete and steel cages reminiscent of prison cells. This outraged many visitors. Animal welfare is a movement based on the desire to reduce animal suffering and to minimize negative impacts that might result from human interactions. The problem with this philosophy is that to some degree it depends on humans being able to assess if they themselves are having a negative impact and are causing an animal to suffer. Suffering can be very subtle, occurring without humans having the capability for observation. The biology of a species must be understood very well to make such a decision. Animal rights is based on the philosophy that each individual animal has rights that morally should not be violated. The problem with this philosophy is that it focuses on the individual exclusively, and also requires a human judgment. In other words, humans must decide on acceptable morals based on human values not the values of each species being regulated. These are very heavily debated subjects that will influence the management of animals in captivity.
Today, many animals and their habitats are threatened with extinction. Most zoos use naturalistic habitats and put animal welfare and conservation at the top of their duties. Ironically, captivity is the only hope for the survival in the wild of an always increasing number of species. Due to this responsibility accepted by zoos today, the famous author, naturalist, and zoo builder Gerald Durrell described them as "stationary arks." If the stationary ark is to remain in place, zoos must continue to produce results in preserving the welfare of captive and wild animal populations. Much of this work cannot be done within the perimeter gates of a zoo. Zoos must house and store healthy animal populations, and they must also give visitors instruction and direction on the mission so it will expand and move beyond the gates. Staff must also be active in worldwide field missions to teach conservation messages. A zoo must also be able to compete and have their voice heard in the global political arena. Ironically, if zoos are successful enough, there will be no need for them.
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American Zoo and Aquarium Association. 8403 Colesville Road, Suite 710, Silver Spring, MD 20910 USA. Phone:(301) 562-0777. Fax: (301) 562-0888. Web site: <http://www.aza.org/>.
Center for Ecosystem Survival. 699 Mississippi Street, Suite 106, San Francisco, 94107 USA. Phone: (415) 648-3392. Fax: (415) 648-3392. E-mail: [email protected] Web site: <http://www.savenature.org/>.
World Association of Zoos and Aquariums. PO Box 23, Liebefeld-Bern CH-3097 Switzerland. Website:<http://www.waza.org>.
Ken B. Naugher, BSc