Violent aggression and combat in all species

Fine weather makes a cruel backdrop to war. For those who watched the Battle of Britain in August 1940, the curlicues of vapour in a cloudless summer sky, the smoke-trails plunging into fields of ripened corn, became images no less indelible than that of New York's horror on a gilded autumn morning. Nature's exquisite indifference can be a part of the pain.

Thallabawn strand, in a run of fine September mornings, presents an almost elegiac beauty - the dunes flooded in fiery light, the small waves suffused with it: a slow, crystal curl and bubbling fall just beyond our shadows. After the month's big tide, the dog and I walk a clean sheet of sand marked only by the little waders sifting in from the north: turnstone, dunlin, plover.

Perversely, its very serenity makes me reach for some instance of violence in the natural world which might come near the shock of current events. I play over beach scenes from Patagonia, where killer whales charge out of the surf to grab baby seals and crunch them up. But that, of course, is no more "aggression" than the robin leaping on a worm.

Biologists have worried away at the myriad aggressions of Earth's species, as if understanding their role in evolution might offer some clue to managing our own inheritance of violence.

The early years of modern ethology - the study of animal behaviour - were greatly influenced by Konrad Lorenz. His book, On Aggression, seemed to say that most non-human nature handles its violent impulses rather more humanely than we do. It stressed the many forms of ritual, non-lethal aggression which mark fighting between animals of the same species.

Their violent combat - in defence of territory, competition for mates or food, or to establish a stable social hierarchy - usually stops short of actual killing.

If growls and roars and body language don't produce a winner, stags lock horns, wolves seize each other by the ruff, bull elephant seals gash each other horribly about the head, but only where their hide can take it. "We have never found," concluded Lorenz, "that the aim of aggression was the extermination of fellow members of the species concerned." The value of letting a vanquished rival off without killing him presents some evolutionary problems, since altruism and mercy seem poor servants to the selfish ambition of genes. The limits to aggression may depend on the lifestyle of the species - whether or not it actually pays, genetically, to be a pacifist.

And in the decades since Lorenz's relatively idealised view of nature, the roster of animal killers has mounted, along with the patient hours of field observation.

In his controversial synthesis, Sociobiology, (1975) Edward O. Wilson judged that "murder is much more common and hence normal in many vertebrate species than in man. I have been impressed by how often such behaviour becomes apparent only when the observation time devoted to a species passes the thousand-hour mark."

"Surplus killing" by foxes and other carnivores has been explained as a near-autonomous reflex in the presence of prey who won't flee, but darker impulses can now be read into the wanton killing among lions, habitual cannibalism among hyenas, thuggery by dolphins, vicious gang attacks among chimpanzees, our closest primate relatives, and the killing and eating of infants among several other ape and monkey species.

The last has been especially upsetting, I imagine, to the women ethologists, such as Jane Goodall and Shirley Strum, who have unravelled so many of the warmer relationships in primate life.

George Schaller, himself an expert on gorillas, insists that primate study "is more than an intriguing scientific exercise, for it emphasises that humankind is not bound by its heritage into using force, that it can choose to live in peace, harmony, co-operation and friendship. A contemplation of baboons can help humankind correct a skewed vision of itself."

Among primates, however, only humans and chimpanzees share in lethal aggression by gangs of males. In the case of chimps, the reasons can be sought in opportunities for mating or better food supply. As with the killing of infants by male primates - apparently aimed at speeding up the fertilization of females - it must now be hard to know what behaviour is truly "natural" and what is a social pathology springing from loss of habitat and persecution in a human-dominated world.

Where all this leaves the terrorists is hard to know. But I cannot find it quite without meaning that the worst act of aggression in contemporary experience has sprung from the heart of a social group that exalts male bonding and dominance and rejects and subjugates the female mind.

An essay on primate infanticide - and widespread occurrence of the practice even in human history - is just one of a legion of revelatory topics in recently published The New Encyclopedia of Mammals. With more than 900 big pages that take two hands to lift, this is an ultimate in natural history books and brilliant proof that knowledge, despite the CD-Rom, still leaps powerfully from the printed page.

Since work on its original edition began 20 years ago, new ideas and techniques in mammal biology have produced a flood of new discoveries, so that 400,000 words of the new encyclopedia are fresh and most of the rest rewritten. It is again edited by David Macdonald, director of Oxford University's Wildlife Conservation Research Unit and a gifted popular communicator.

His high standard of readability runs right through the expert contributions to this massive book, from aardvark to zorro (a South American fox), helped by dazzling photographs and artwork and a fine instinct for organising information.

While specialist readers may focus on the new developments in taxonomy and the ordering of something over 4,600 species, the general reader is free to browse on the diving exploits of sperm whales or the scent-based language of house mice.

The book, as Macdonald says, is rich in vivid images of the "savagery, menace and treachery" of much mammal life, but also in the harmonies and subtle altruisms that the science of ethology is unravelling. If the world is in the right mood at Christmas, this could be a gift to remember.

The New Encyclopedia of Mammals published by the Oxford University Press (£35 in the UK)

Eye on Nature is edited by Michael Viney, who welcomes observations sent to Thallabawn, Carrowniskey PO, Westport, Co Mayo. E-mail: viney@anu.ie

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