A good zoo aims to serve four things: amusement, education, science and conservation. Every time I consider the way zoos work on these laudable notions I think of eagles. In what way is an eagle in a cage amusing? What can we learn from it? In what way does its life help the lives of wild eagles? What does the spectacle of a caged eagle teach children? How large should an eagle's cage be? Ten square miles would be hardly big enough. "Robin redbreast in a cage puts all heaven in a rage," Blake wrote: divine fury at the incarceration of eagles should be enough to destroy the galaxy.
Education? A piece of scholarly research on a zoo in Buffalo, New York, found that the most common expressions used to describe animals were: cute, funny-looking, lazy, dirty, weird and strange. I do not feel that it is worth locking up eagles to assist people in reaching such conclusions. The truth is that zoos do not celebrate animals: they celebrate man's dominion over nature. It is hardly necessary to stress this dominion in the dying years of the 20th century. Virtually every square centimetre of the globe has been shaped by the hand of man. Such wilderness as we have left exists only by man's express permission.
Zoos emphasise the gulf between man and the natural world. Dale Jamieson, a professor of philosophy, wrote: "Zoos teach us a false sense of our place in the natural order. The means of confinement mark a difference between humans and animals. They are there at our pleasure, to be used for our purposes. Morality, and perhaps our very survival, require that we learn to live as one species among many rather than as one species over many."
Zoos can be used to teach. Early delight in the Snowdon aviary at London zoo was part of my education. But too much of what zoos teach is unacceptable. Even in the free-flight cages, one asks: are we really teaching about birds? Or the wonders of human ingenuity?
Birds have delighted us throughout history because they can fly: they express mystery and freedom. Locking up a bird - say, a bird genetically programmed to migrating thousands of miles a year - seems no more than an experiment in avian sanity. Zoos know this, and have tried to offer the animals a more enlightened captivity. But even the zoo's main self-justification, the breeding of rare mammals and birds, can seem no more than a further celebration of man's manipulation of the world to his pleasures.
Conservation is the thing. Zoos do their best for conservation, but they are carrying too much weight for the course. The saving from extinction of PÅre David's deer, the European bison and the Mongolian wild horse are down to zoos. However, it is not strictly necessary to cage eagles in order to save horses. If you want to save mammals and birds from extinction, the answer is not to shoot their mothers, capture their offspring, transport them overseas and try to breed from them. The answer is to save their habitats.
If there is a place for zoos at all, it is as centres of campaigning and education. The number of species of mammals and birds that can live a decent life in a zoo is seriously limited. Zoos must be rethought from top to bottom if there is to be any point to them at all. London zoo has launched ú13 million appeal to carry on as it always has done. Just think what all that money could do for real conservation. I do not think that ú13 million should be given to support a rather degrading form of public entertainment. If you want to spend that kind of money on nature, then spend it to protect places where eagles fly free.
Jamieson said: "Because what zoos teach us is false and dangerous, both humans and animals will be better off when they are abolished." Abolished or rethought. It is better to save a mountain than cage an eagle.
