The word ‘Conservation’ is bandied about a lot these days. It is a fashionable word, like the word ‘green’. It is a word that suggests a rather selfless dedication towards protecting wildlife and wild places. A lot of zoos use the word conservation to describe their role in society. ‘Our Aim is to Assist in the Conservation of Endangered Species by Captive Breeding’ proclaims a sign at one menagerie that is not included as a good zoo in this guide. It is a questionable claim.

But who can blame hard-pressed zoo directors for climbing onto the green bandwagon. It only costs a few pounds, after all, to put up a sign claiming to be a ‘conservation zoo’, and from then on any zoo can bask in the reflected glory of those few collections which really are committing resources towards breeding endangered species. The word conservation has become common and cheap. The act of conservation, alas, is rare and brutally expensive.

To begin with there is the cost of the animals themselves. Even in these days of breeding loans and co-operative species management, animals are still bought and sold. The rarer the animal, the higher is the asking price. The entire animal stock of the Zoological Society of London at Regent’s Park and Whipsnade was valued in 1958 at £174,618. Today a single female okapi might fetch over £150,000 if sold. Add to that the cost of transport, the building of special crates, quarantine expenses, insurance, dealer’s profits and a huge amount of paperwork. You may begin to realise that starting a zoo for endangered species is far from cheap. When John Aspinall chose to bring two Sumatran ‘woolly rhinos’ from Indonesia to his zoo at Port Lympne in 1986, the operation is said to have cost him almost two million pounds.

And then there is another, subtler, cost. This is what John Knowles of Marwell Zoo calls ‘deficit financing’. It works like this: imagine that a scimitar-horned oryx costs, say, £50 a week to maintain in food, housing, keeping, and veterinary costs. A doubling of your herd will double your costs, but visitors like to see a lot of species, not a few huge herds. They are apt to become bored by a succession of cages all occupied by an identical cat asleep in an identical corner. A good zoo director will know that numbers are almost always critical to breeding success in the long term. But a herd of thirty oryx will attract not one more visitor than a herd of fifteen, or a family of four. So how does a zoo justify the keeping of these ‘uneconomic’ groups?

The answer is that justification has to be made on conservation, not on economic grounds. Deficit financing means that popular animals like monkeys, sealions, penguins and giraffe generate the income by attracting visitors, and the surplus goes towards maintaining the ‘uneconomic’ herds that have less popular appeal.

There is one major drawback to this approach, and it has to do with competition. If the zoo down the road has the same popular animals as yours but does not choose to spend its money on conservation-sensitive creatures, then down comes its gate price, up goes its market share, down comes your market share, and out of the window go all your conservation ideals. The brutal law of the market place prevails. In the final analysis, the big crowds go to a zoo for a good day out, not for the warm glow they might get from having contributed towards saving an endangered animal; and while it is true that millions go to a zoo every year, they do have a great many collections to choose from, to say nothing of a growing number of theme parks and other attractions, and competition can be fierce. These days it is as much as many zoos can do to stay in business from one season o the next, let alone to commit substantial amounts of their scarce resources towards keeping a species that the public has probably never heard of, just because it is endangered.

So you see why it is cheaper just to put up a sign.

All of which is bad news for conservation, and ultimately bad news for the zoos themselves. Because, despite everything, captive breeding of endangered species, once the bete-noire of many conservationists, is rapidly becoming more and more important. Consider the Humboldt’s penguin. Almost everywhere you go you can see Humboldt’s penguins, and a great many European and North American collections exhibit them. Their popularity in zoos has been, in part, due to their abundance in the wild, and back in the old collecting days they were fairly easy to come by. They come from the Pacific Coasts of South America where they feed in the fertile coastal waters and nest in burrows on the shore. Over the past decade the wild population has collapsed dramatically. Over-fishing, coastal development, and pollution are blamed for the penguins’ decline, and a recent estimate put the wild population at two thousand pairs, with a continuing fall expected. What this illustrates is that the time-honoured complacency of many zoos that some species will always be in plentiful supply is now on shifting sand. Nowadays hardly any species can be taken for granted, not even penguins; and if the zoos don’t breed them, then there will soon be plenty of empty penguin pools all around the world.

So, in a crude fashion, the zoos themselves have a nettle to grasp, just to keep themselves in stock into the next century. But, alas, the problem goes a great deal deeper than that. There is now a real likelihood that many vertebrate species will soon only exist in captivity.

The human population of the world is to blame. The World Bank has estimated that population will level off at around ten to twelve billion towards the end of the next century. Most of the expected increase will be in the poorer countries of the world, often countries rich in wildlife. Just consider the impact that five billion people have already had upon Planet Earth, and multiply that effect by three: three times the demand for food and farmland and fresh water and firewood, three times the demand for raw materials, housing, and roads. Imagine the effect that this is going to have upon the rate of forest destruction, (already proceeding at fifty acres a minute), on over-fishing, pollution, poaching. The spectre of such a world may seem alarmist, but perhaps we could all do with a little alarmism. Freud wrote that we should ‘think the unthinkable, and then plan for it.’ But how do you plan against the imminent wholesale extinction of hundreds, maybe thousands, of animal species?

One plan might be to keep a safe reservoir of every species likely to become threatened, in safe havens, closely managed to protect against in-breeding and disease. This is another way of saying perhaps we should keep animals in zoos. A recent report predicts that we shall need to keep around two thousand species of large terrestrial animals in captivity for five hundred years or more if we are to save them forever from extinction. It is a tall order. But can it be done?

To begin with, we would need a reasonable captive population of each species. This is necessary to prevent inbreeding. Curiously, populations can often survive well even if they all derive from a very small number of founding parents. Every Arabian oryx alive is descended from a single herd of nine and every Pere David’s deer from a herd of eighteen. But if the number of animals stays low for more than a few generations, the problems of inbreeding may prove fatal. The solution is to establish a large zoo population of each threatened species as swiftly as possible, and then to circulate animals between the zoos to keep the populations genetically diverse and healthy. Zoologists disagree about the minimum size of a zoo population needed to provide a secure future, but the consensus seems to be that at least one hundred breeding individuals are essential and over three hundred would he desirable’

There are estimated to be slightly more than a quarter of a million animals in the zoos of the world. If every one of these were to be included in an organised captive-breeding programme, and if populations were to average around 275 individuals, simple mathematics show that no more than 925 species could be saved. Gerald Durrell once called zoos ‘Stationary Arks’. It looks as though they will be crowded. In fact, if they are to function successfully, we may need twice as many.

However, not all countries are alike in this regard. The United Kingdom, for example, already has around 50,000, animals in their zoos, about a fifth of the world’s zoo population. Maybe they have more than their fair share. Some zoo directors clearly think so. It all comes back to the question of competition. So long as the public is sufficiently uncritical there will be plenty of zoos to satisfy the demand for lions and llamas and all the other common species that breed so prolifically in captivity that they are both cheap to acquire, and are of little conservation value. In a very real sense these zoos are acting in a manner that is directly contrary to their often stated conservation aims. By competing directly against the good zoos, they deny them the income they need. They also help to create a climate of opinion that regards zoos at best as places that do no more than indulge our curiosity, and at worst as animal prisons and consumers of wildlife.

All of this leaves serious zoos looking for alternative sources of finance. Gate receipts will not finance conservation until the public becomes more discerning.

Many national zoos and collections are supported by their national or regional governments.  Zoos like Washington’s Smithsonian ‘National Zoo’, and Paris’ Jardin des Plantes are often simply an extension of the National museums. Some, like Houston Zoo, are operated by a city or a state. Many other zoos benefit from tourist board, or development agency grants. This can help provide some of the financing that the real conservation work demands.  But in reality, most zoos have to face the real world, and be self financing. It is an uncomfortable fact that conservation work may depend ultimately upon the ability of good zoos to attract paying visitors. Lose the visitors, and maybe we shall lose the black rhino, or the Mauritius kestrel. Elsewhere the only real evidence of dedication to captive breeding has come from the personal commitment of enterprising or wealthy men: men like the late Sir Peter Scott who founded the Wildfowl Trust at Slimbridge in England, and whose contribution towards rescuing the Hawaiian Goose from the very brink of extinction has been the inspiration for many other projects: men like Gerald Durrell, the best-selling author, John Knowles, a wealthy farmer, or John Aspinall, a millionaire club-owner.

The potential role of zoos as agents of conservation has not always appealed to all conservationists. Essentially all that zoos can do is to preserve a population of animals in close captive management, while the real source of the problem, habitat destruction or over-exploitation, goes unchecked. A common argument against this form of species preservation goes like this: all the money invested and spent annually on zoos would be far better spent actually preserving habitats. Surprisingly, perhaps, few zoo people would dispute this fact. However, it is rather like arguing that all the money spent upon slimming aids would be better spent helping to alleviate world hunger. The alternative is an artificial one.  The millions of  zoo visitors world wide who pay good money for their day out are doubtless canvassed by conservation charaties for donations, but that is not how they choose to spend their money on a sunny weekend. We would do better to recognise that there are zoos that do spend our money wisely, and to direct our visits towards them. That is what this guide aims to help us do.

When habitats come under threat, it is invariably the bigger animals that go first because their demands upon the environment are the greatest. These are creatures that zoos are often in a position to help. Already there have been some astonishing successes. Without captive management we would no longer be sharing our planet with Pere David’s deer, American or European bison, Przewalski’s horse, Arabian or scimitar-homed oryx. Island species are also important candidates for captive conservation. Species saved include the Hawaiian goose, the Jamaican boa, and the Mauritius pink pigeon. Some re-introductions have already taken place, but in the short term we should not expect too many of these. After all, if animals have become extinct in a habitat, the reason for the extinction needs to be removed before the species can be returned. Nevertheless, good zoos have proven that they can be a reservoir for endangered species. Now they face up to their greatest challenge, to sustain up to two thousand species, in close management, perhaps for centuries.

There are encouraging signs. The best of these is the international effort being made to co-ordinate breeding programmes for the most crucial species, and by the Joint Species Management Programs, which aim to focus the attention of good zoos upon sharing their precious animals to improve their long-term chances of survival. Good zoos now take their role as a conservation resource very seriously. Many more animals are now swapped or placed on breeding loans than ever before. Success in breeding even traditionally difficult species like cheetah is now rapidly improving. The vast majority of zoo animals were themselves bred in captivity. They belong to the early generations of a time-bridge that may have to span several centuries before their distant descendants once again twad the wild soils of their native lands.

The Vocabulary of Extinction

The journey from abundance to extinction can be a very rapid one. It took less than fifty years for the passenger pigeon to fall from being the most abundant species of bird on earth, to becoming extinct. So when we say that an animal species is ‘In Danger of Extinction’, how far along this road has it travelled, and how much further does it have to go?

To help discuss these issues, conservationists use the following terminology:

A species is abundant if, like mankind or the brown rat, it seems destined to be around for the foreseeable future.

A species is extinct if, like the passenger pigeon or the quagga, there have been no confirmed sightings for fifty years.

A species is endangered if its continued survival is unlikely should the factors causing its reduction in number continue to operate. The black rhino is an endangered species; so is the Siberian tiger, and the Californian condor.

A vulnerable species is one that is likely to become endangered soon if the cause for its decline continues. The African elephant is a vulnerable species, and so is the jaguar, and the white eared pheasant.