Two and a half decades ago, when I was a novice undergraduate at George Washington University, the study of live primates, even chimpanzees, held no interest for me. My dream then was to be a paleoanthropologist stalking the remains of early hominids somewhere in East Africa. So I, like many others of my age and era, spent my time locked within stark academic walls that narrowed my focus to primate graveyards and asylums which, back in the naive 1960s, I knew only as museums and zoos.

When I first travelled to East Africa in 1968 to study chimpanzees in the wild at Gombe National Park in Tanzania (which happened at the urging of Louis Leakey who, perhaps weary of my persistent postal pursuit of a digging career in Olduvai Gorge, unexpectedly forwarded me to Jane Goodall), my graduate studies at Pennsylvania State University nearly ended due to strong professorial objections that two years with wild chimpanzees would be a waste of time. Only the intervention of Ray Carpenter, who alone endorsed what others saw as useless diversion, kept me enrolled as a student of physical anthropology.

At Gombe, my interest in dead things waned and a stronger fascination with living beings emerged. The close associations I experienced with those chimpanzees altered my views in ways both basic and broad, leading me, albeit some years after my departure from Gombe in 1971, to shift from an aspiration to be a scientist toward a truer vocation to be a conservationist.

No single event caused that change of heart and mind, but one evening in the Gombe hills is embedded in my memory as a seed of transformation. Seeking a brief respite from months of continuous chimpanzee following, I took a rare day off to climb one of the steep ridges leading upward to the high rift escarpments that demarcated the eastern boundary of the park. As I sat alone at the crest of a grassy ridge watching a spectacular yet common sunset over the silvery waters of Lake Tanganyika in wonderful solitude and silence, I suddenly noticed two adult male chimpanzees climbing toward me on opposite slopes. They saw one another only as they topped the crest, just yards from my seat beneath a tree, whereupon both suddenly stood upright and swiftly advanced as bipeds through waist-high grass to stand close together, face to face, each extending his right hand to clasp and vigorously shake the other's while softly panting, heads bobbing. Moments later they sat down nearby and we three watched the sunset enfold the park. When dusk fell my two companions went off to build platform nests high in the trees of the valley. Nevermore, I realised as I hastened homeward to my own bed (a lower platform) at the field station before darkness fell, would I regard chimpanzees as 'mere animals'. On that singular eve, which also marked the twilight of my youth, I had seen my species inside the skin of another.

But for minor differences — a few inches in height, some extra body hair - there on a ridge in Africa had stood two colleagues performing a greeting ritual seen daily on any campus in America. Science was not a key to insight on that occasion, and anthropomorphism was for me a moot issue. The episode, and others like it later, forged a familiarity with individuals which eventually coalesced as a profound respect for a kindred species. And that, in turn, spawned a lifetime commitment to raising survival odds for all chimpanzees.

By every criterion ever devised to set humankind on the apex of species development - behavioural, social, psychological, biological -chimpanzees qualify as the closest living relatives we humans have on this planet. Not the same, inasmuch as every species by definition is distinctive, but extraordinarily similar - neighbours, so to speak, on a planetwide spectrum of diversity.

Scientific evidence confirming the close kinship can be seen in a wide range of shared traits. Example: chimpanzees exhibit many technical skills, from using stone implements to making assorted plant tools for specific purposes, which are acquired by learning and feature cultural variation. Example: chimpanzees share with us many cognitive abilities, such as long-term memory, self-recognition, sense of humour, even some elements of linguistic talent. Example: chimpanzees are so close to humans in body structure and chemistry that blood transfusions and organ transplants are feasible. Example: many emotional states are so alike for both chimpanzees and humans that each intuitively understands how to interact with the other. The list of similarities is long even if only the scientifically verifiable traits are cited; it becomes much longer if anecdotal observations are also accepted as a valid basis for comparison.

We humans commonly react with astonishment upon discovering that chimpanzees can do something we consider special to humankind. Any evidence of intelligence overlap provokes the greatest scepticism, as the uniqueness of that quality in us is our most cherished illusion. But is this defensive reaction anything more than a visible indicator of our anthropocentric view of the world? Would it not be more extraordinary if a species having broad genetic overlap with us did not perform acts or feel emotions or have thoughts akin to ours?

The prejudice we invoke to collectively degrade other species, and sometimes to selectively demean human populations, is embedded in our cultural heritage. Pejoratives such as 'vicious as a dog' and 'stupid as a baboon' reflect common themes in human societies. Intimate familiarity with individuals, human or nonhuman, is the key to shedding such prejudices as unfounded myths.

Having spent some years in the company of chimpanzees, both free and confined individuals, I find myself no longer able to cleave to the majority human view of chimpanzees as inferior beings. When I am asked today, twenty-four years after my first trip to Gombe, what drives my personal concern for chimpanzee welfare and survival, I can only reply: 'Individuals whom I know or may some day meet.' And therein lies the essence of the lesson I learned at Gombe, where each chimpanzee was special in character and also vital to community life. Knowing individuals, I cannot continue thinking in terms of abstract prejudice. My view of chimpanzees is much like my view of humans: some are scoundrels and some are saints, and most are somewhere between those extremes.

To allay critics who would say that I merely have acquired a pancentric bias, a shift of allegiance from human to chimpanzee, I should add that I view dogs in my neighbourhood much the same way because I also know them as individuals. Familiarity with the members of any group or population or species is, to me, the main antidote to indifference about the well-being and the survival of others. Had I never met a chimpanzee on equal terms, in a setting of mutual freedom, I might well have retained my ingrained anthropocentric prejudices without regret.

Much as I would prefer to believe otherwise, there is little doubt in my mind that the increasingly fragmented populations of chimpanzees that are so thinly dispersed across equatorial Africa will face extinction in the foreseeable future. The scenario being sketched by primatologists is grim at best, with land degradation and resource exploitation accelerating the demise of chimpanzee habitats and communities everywhere.

So long as humans continue to reproduce at the current rate, there can be no safe haven on the planet for other large mammals. Equatorial Africa today contains at least 300 million humans compared with less than 300 thousand chimpanzees. That thousand-fold gap widens further as humans increase at a rate of 3.1 per cent per annum and chimpanzees decrease ever more precipitously each year. If the trend continues, is it not fanciful to expect there to be room for chimpanzees anywhere in Africa by the end of the century?

In their wilderness retreats, free chimpanzees are under assault by waves of humans bearing hoes, saws and guns. Few chimpanzee communities in Africa are today safe from human encroachment and persecution. The national population estimates ring alarm bells. In the twenty-five nations encompassing the historical range of the species, four contain no chimpanzees and fifteen others retain less than 5,000 chimpanzees apiece. Survival is not assured even in the six remaining nations where populations are still relatively intact, due to recent sales of extensive timber concessions.

During the early 1980s a survey of Gabon, containing some of the best habitats, yielded an estimate of about 64,000 free chimpanzees. Biomedical scientists, whose interest in these apes has always been a consuming one, promptly cited Gabon as proof that Africa still has a 'plentiful supply' of free chimpanzees available for 'harvesting' to save human lives. But by April of 1988 the surveyors, Caroline Tutin and Michel Fernandez, stated that 'in the five years since completion of the census the situation has changed' so much that 'by 1996 the chimpanzee population of Gabon will be reduced by at least 20% as a result of habitat alteration caused by selective logging'. Other major population nucleuses in Cameroon and Zaire are similarly threatened by rapid change.

In their prison settings, confined chimpanzees continue to suffer abusive treatment, social isolation, mental deprivation, emotional trauma and the like. I estimate that between 4,000 and 5,000 chimpanzees exist worldwide in medical institutions, zoological exhibits, roadside menageries, entertainment compounds and the homes of pet owners. Conditions of confinement may vary but it is a clear truth, in my mind, that no imprisoned chimpanzee today receives what I would regard as optimum living conditions and proper treatment.

The plight of chimpanzees in medical laboratories causes me the greatest concern. In the United States, where captive census data are most readily available, about 2,000 of 3,000 confined chimpanzees exist in biomedical facilities. It is indeed a sad statement on human values that the very institutions which proclaim a dedication to alleviating suffering and pain in humans cause so much distress to chimpanzees. And it is equally perplexing that medical scientists are the most dedicated opponents to the enacting of legislation designed to better protect free chimpanzees and improve the treatment of confined chimpanzees. I rest my case on two examples of this remarkably inconsistent position.

First, after several conservation groups petitioned the US Department of Interior's Fish and Wildlife Service to place chimpanzees on the endangered list under the Endangered Species Act, the government received 54,212 letters of support and only nine letters of dissent in 1988. Supportive letters included many from a wide range of institutions, but no biomedical facilities, while opposing letters included eight from biomedical research centres and one from a circus. Acting on behalf of the medical community, the government's National Institutes of Health mounted an intensive lobbying campaign to convince Congress that endangered status was not warranted due to presence of an 'ample supply' of chimpanzees in Africa. Because the figures collected from thirty-nine field scientists could not be easily disputed, some members of the biomedical community attacked the credibility of the field experts instead.

Second, five years after the US Senate passed amendments in 1985 requiring laboratories to provide 'a physical environment adequate to promote the psychological well-being of primates', the US Department of Agriculture proposed new regulations under the Animal Welfare Act. The delay was caused by medical opposition on an unprecedented scale. The regulations were revised many times in public reviews that produced some 12,000 letters to the US Department of Agriculture. One round of proposals published on 15 August 1990 yielded 1,372 institutional criticisms plus an uncounted number of personal objections from the medical research community. Tremendous lobbying pressure was directed at Congress to press the US Department of Agriculture into submission. Capitulation occurred by 15 February 1991. The final regulations adopted wholesale the minimum standards of maintenance and care set many years ago by the government's National Institutes of Health. For instance, the recommended cage size for permanently confining a single adult chimpanzee remained at a meagre 5x5x7 feet and even infants were not guaranteed social housing.

The connecting link between freedom and confinement is the pipeline of international commerce which causes chimpanzees more suffering and trauma than the conditions they face at either end. Dealers who stop at nothing, least of all legal barriers, to pursue their greed for cash profits, and clients who shut their eyes to the most cruel and destructive methods of acquisition so as to maintain a fantasy of propriety, work together to keep this pipeline open no matter how many anti-trafficking laws are enacted.

Based on hard evidence from a wide range of sources I can confirm that at least ten chimpanzees die for every infant that survives more than a year at the final overseas destination. If a nation such as Sierra Leone, where I served for four years as a national park director and thus had access to official records, verifiably exports as many as 3,000 infants in two decades then it is an absolute fact that some 30,000 chimpanzees were exterminated from that region in the process. Were it not for the anthropocentric blinkers we put on to hide from such realities, that alone should have prompted a general indictment of the idea that chimpanzees can be legitimate objects of trade. The raw details warrant far harsher public condemnation, however, as the modern chimpanzee trade closely resembles the methods and motives of the historical slave trade.

Most prized by dealers and their clients are nursing infants who are less than two years of age and totally dependent on their mothers for survival. The slaughter begins in the wilderness as hunters with shotguns or flintlocks loaded with pebbles or metal shrapnel attack mothers and other protective group members. Many infants die when this crude ammunition scatters to hit both mothers and their clinging offspring. Pit traps, poisoned food, wire snares, nets and even dog packs are also used to kill adults defending the youngsters. More deaths occur during transport to villages. Infants are often tied hand and foot with wire, causing circulation loss and septic wounds, and are trucked to urban centres in tiny cages or tightly bound sacks, often under heavy suffocating loads to avoid detection at checkpoints. Few receive care en route, so starvation and dehydration are commonplace. While awaiting shipment overseas, more die of neglect in filthy holding pens and at airports where flight delays lead to exposure. Cramped in tiny crates, even carried in personal luggage, the victims often must endure days of travel through several transit points which offer ample opportunities for falsifying documentation. Some infants manage, against all odds, to survive this ordeal only to die at the final destinations from cumulative physical and psychological trauma.

If we consider that most of the 4,000-5,000 chimpanzees now held in confinement worldwide originated in West Africa, it is easy to see that 40,000 or more were exterminated there by commercial trade in about twenty years — the span of a single chimpanzee generation. When other decimating factors are added, is it surprising that the western subspecies accounts for only 10 per cent of the total number surviving in Africa?

My work on chimpanzee survival and well-being issues these past years has yielded some insights but no simple solutions to this terrible situation. I do believe, however, that every chimpanzee has rights to the freedom and the self-determination we so highly value for ourselves.

And because I see chimpanzees as individuals, some of whose experiences and memories I share, I feel a moral obligation to respect the members of a kindred species.

Looking at chimpanzees from where I stand, eye to eye, not down my sharper human nose, I consider it sheer arrogance to perpetuate the anthropocentric views established by my ancestors simply because that was the collective human impulse. As Pogo once said in a memorable cartoon: 'We have met the enemy and they are us.'