But if the accidental death took place in autumn or early winter, there was always the possibility that the body of the dead animal would be quickly covered with a layer of sticky mud that would freeze when hard winter came. Thus the corpse would be preserved in what amounted to a deep freeze, with decay impossible. Most often, one has to suppose, spring and summer would bring a thaw; the protective mud would lose its ice crystals; and the dead body would decompose. Disintegration of the corpse would proceed as always, except that the freezing would have postponed it for a season.
However, on rare occasions, which could become quite numerous over a time span of a hundred thousand years, that first immediate freezing would for some reason or other become permanent, and now the dead body would be preserved intact for a thousand years, or thirty thousand, or fifty. And then, on some day far distant when humans ranged the valleys of central Alaska, some inquisitive man would see emerging from a thawing bank an object that was neither bone nor preserved wood, and when he dug into the bank he would find himself facing the total remains of a woolly mammoth that had perished in that bank thousands of years before.
When the accumulation of viscous mud was carefully cleaned away, a remarkable object would be revealed, something unique in the world: a whole mammoth, long hair in place, great tusks twisting forward and meeting at the tips, stomach contents intact from the time it last grazed, massive teeth in such perfect condition that its age at death could be accurately calculated within five or six years. It was not, of course, a standing animal, plump and clean and encased in blue ice; it was lying on its side, plastered with mud, with leg joints beginning to come apart, but it was a complete mammoth, and it revealed to its discoverers a volume of information.
This next point is important. We know about the great dinosaurs who preceded the mammoth by millions of years because over the millennia their bones have been invaded by mineral deposits that have preserved the most intimate structure of the bone. What we have are not real bones but petrified ones, like petrified wood, in which not an atom of the original material remains. Until a recent find in far northern Alaska, no human being had ever seen the bone of a dinosaur, but everyone could see in museums the magically preserved petrifications of those bones, photographs in stone of bones long since vanished.
But with the mammoths preserved by freezing in Siberia and Alaska, we have the actual bones, the hair, the heart, the stomach—a treasury of knowledge that is incomparable. The first of these icy finds seems to have occurred by accident in Siberia sometime in the 1700s, and others have followed at regular intervals thereafter. A remarkably complete mammoth was uncovered near Fairbanks in Alaska not long ago, and we can anticipate others before the end of the century.
Why has it been the mammoth that has been found in this complete form? Other animals have occasionally been uncovered, but not many and rarely in the excellent condition of the best-preserved mammoths. One reason was the substantial numbers of the breed. Another was that the mammoth tended to live in those peculiar areas where preservation by freezing mud was possible. Also, its bones and tusks were of a size to be durable; many birds must have perished in these areas in these times, but because they had no heavy bones, their skeletons did not survive to keep their skin and feathers in position. Most important, this particular group of mammoths died during a time of glaciation when instant freezing was not only possible but likely.
At any rate, the woolly mammoth served a unique function, one of inestimable value to human beings; by freezing quickly when it died, it remained intact to instruct us about life in Alaska when the ice castle functioned as a refuge for great animals.
One day in late winter, twenty-nine thousand years ago, Matriarch, a mammoth grandmother, forty-four years old and beginning to show her age, led the little herd of six for which she was responsible down a softly rolling meadow to the banks of a great river later to be known as the Yukon. Lifting her trunk high to sniff the warming air and signaling the others to follow, she entered a grove of willow shrubs that lined the river, and when the others had taken their places beside her, she indicated that they might begin feeding on the sprouting tips of willow branches. They did so with delight because they had subsisted on meager rations during the recent winter, and as they gorged, Matriarch gave grunts of encouragement.
She had in her herd two daughters, each of whom had two offspring, a heifer and a bull. Discipline was enforced by Matriarch, for it was the females who had the responsibility for rearing and educating the young. The males with their tremendous showy tusks appeared only in midsummer for the mating period; the rest of the year they were nowhere to be seen.
In obedience to the instincts of her race, and to the specific impulses that stemmed from her being female, she devoted her entire life to her herd, especially to the young. She weighed, at this time, about three thousand pounds, and to keep alive she required each day one hundred and sixty pounds of grass, lichen, moss and twigs. When she lacked this ample supply of food she experienced acute pangs of hunger, for what she ate contained only minimum nourishment and passed completely through her body in less than twelve hours; she did not gorge and then ruminate like other animals, chewing her cud until every shred of value was extracted from it. No, she crammed herself with vast amounts of low-quality food and quickly rid herself of its remains. Eating had to be her main preoccupation.
Nevertheless, if in her constant foraging she caught even a hint that her four grandchildren were not getting their share, she would forgo her own feeding and see to it that they ate first. And she would do the same for young mammoths who were not of her own family but under her care for the moment while their own mothers and grandmothers foraged elsewhere.
This selflessness, which separated her from other mammoth grandmothers, had developed because of her monomaniacal affection for her children. Years ago, before her youngest daughter had borne her first offspring, a once-prepotent older bull joined her herd during the mating season, and for some inexplicable reason, when the mating was completed, he remained with the herd, when normally he should have left to join the other bulls, who foraged by themselves until the next mating season came around.
Although Matriarch had made no objection when this old bull first appeared on the scene to court her daughters—three at that time—she grew restless when he stayed beyond his welcome period, and by various ways, such as nudging him away from the better grass, she indicated that he must leave the females and their children. When he refused to comply, she grew actively angry, but she could do nothing more than show her feelings, because he weighed half again as much as she, his tusks were enormous, and he was so much taller that he simply overwhelmed her in both size and aggressiveness. So she had to be content with making noises and venting her displeasure by rapidly thrashing her trunk about.
But one day as she was eyeing this old fellow, she saw him roughly shove aside a young mother who was instructing her yearling daughter. This would have been acceptable, for bulls traditionally commandeered the better feeding grounds, but on this occasion it looked to Matriarch as if the bull had also abused the yearling, and this she could not tolerate. With a high, piercing scream she lunged right at the intruder, disregarding his superior size and fighting ability, and she was so intent on protecting her young that she drove the bull back several paces.
But he, with his greater strength and immense crossed tusks, quickly asserted his authority and, in a punishing counterattack, slashed at her with such great force that he broke her right tusk at about the halfway mark. For the rest of her life she would be a mammoth cow with a tusk and a half. Unbalanced, awkward-looking when compared with her sisters, she moved across the steppe with the short, jagged tusk, and the loss of its balancing weight caused her to compensate by tilting her massive head slightly to the right, as if she were peeking with her squinty little eyes at something that others could not see.
She had never been a graceful creature. She did not have the impressive lines of her elephant for
ebears, for she was a kind of lumbering triangle, with the apex at the top of her high-domed head and a long, sloping drop from high forequarters to a dwarfed rear end. And then, to make her appearance seem almost formless, her entire body was covered with long and sometimes matted hair.
* * *
In these years when the ice age was at its maximum, Matriarch had at her disposal a somewhat more hospitable terrain on which to feed her family than the harsher one mastodons had known. It was still a four-part terrain: Arctic desert at the north, perpetually frozen tundra, steppe rich with grasses, strip with enough trees to be called a woodland or even a forest. However, it was the steppe that had grown in size, until its mixture of edible grasses and nutritious willow shrubs provided ample forage for the mammoths who roamed it.
Indeed, the expanded area proved so hospitable to these huge creatures that later scientists who would try to reconstruct what life in Alaska was like twenty-eight thousand years before would call the terrain the Mammoth Steppe. In these centuries it looked as if the mammoths, along with the caribou and antelope, would always be the major occupiers of the steppe named after them.
Matriarch moved about the steppe as if it had been created for her use alone. But she conceded that for a few weeks each summer she required the presence of the great bulls who otherwise kept to themselves on their own feeding grounds. But after the birth of the young, she, whose responsibility it was to choose the feeding grounds, gave the signal when her family must abandon areas about to be depleted in search of more fertile land.
A small herd of mammoths like the one she commanded might wander, in the course of a year, over more than four hundred miles, so she came to know large parts of the steppe. The richer parts of this steppe provided a variety of edible trees whose ancestors the vanished mastodons might have known—larch, low willow, birch, alder—but recently, in a few choice spots protected from gales and where water was available, a new kind of tree had made its tentative appearance, beautiful to see but poisonous to eat. It was especially tempting because it never lost its leaves, which were long and neeclelike, but even in winter when the mammoths had little to eat they avoided it, because if they did eat the attractive leaves, they became sick and sometimes died.
It was the largest of the trees, a spruce, and its distinctive aroma both attracted and repelled the mammoths. Matriarch was bewildered by the spruce, for she noticed that the porcupines who shared these forests with her devoured the poisonous leaves with relish, and she often wondered why. What she did not notice was that while it was true the porcupines did eat the needles, they climbed high in the trees before doing so. The spruce, just as clever in protecting itself as the animals that surrounded it, had devised a sagacious defensive strategy. In its copious lower branches, which a voracious mammoth could have destroyed in a morning, the spruce concentrated a volatile oil that rendered its leaves toxic. This meant that the high upper branches, which the mammoths could not reach even with their long trunks, remained palatable.
In the few places where the spruce trees thrived, they sometimes became part of a remarkable phenomenon. From time to time during the long summers when the air was heavy and the grasses and low shrubs tinder-dry, a flash would appear in the heavens followed by a tremendous crashing sound, as if a thousand trees had fallen in one instant, and often thereafter fire would start in the grass, mysteriously, for no reason at all. Or some very tall spruce would be riven, as if a giant tusk had ripped it, and from its bark a wisp of smoke would issue, and then a little flame, and before long the entire forest would be ablaze and all the grassy steppe would be on fire.
At such moments—Matriarch had survived several such fires—the mammoths had learned to head for the nearest river and submerge themselves to their eye level, keeping their trunks above the water for air. For this reason lead animals, like Matriarch with her brood, tried always to know the location of the nearest water, and when fire exploded across their steppe they retreated to this refuge.
Late one summer, when the land was especially dry, and darts of light and crashing sounds filled the air, Matriarch saw that fire had already started near a large stand of spruce trees, and she knew that before long the trees would burst forth in tremendous gusts of flame, trapping all living things. So she began herding her charges back toward where she knew there was a river, but the fire spread so swiftly that it engulfed the trees before she could rush clear of them. Overhead she heard the oils in the trees explode, sending sparks down into the dry needles below. Soon both the crowns of the trees and the carpet of needles below were aflame, and the mammoths faced death.
In this extremity, with acrid smoke choking her, Matriarch had to decide instantly whether to lead her herd back out from among the trees or straight ahead toward the river. Whatever her reasoning, she made the right decision. Bellowing so that all could hear, she headed right for a wall of flame, broke through and found a clear path to the river, where her companions plunged into the water while the forest fire raged around them.
Now came the amazing part: Matriarch had learned that terrifying though the fire had been, she must not abandon this ravaged area, for fire was one of the best friends the mammoths had and she must now teach her young how to capitalize on it. As soon as the flames abated—they would consume several hundred square miles before they died completely—she led her charges back to the spot at which they had nearly lost their lives, and there she taught them how to use their tusks in stripping lengths of bark from the burned spruce trees. Now, purified by the fire that had destroyed the noxious oils, the spruce not only was edible but was a positive delicacy, and the hungry mammoths gorged on it. It seemed as if the bark had been toasted specifically for them.
When the fire was totally out in all parts, Matriarch kept her herd close to the burned-over areas, for the mammoths had learned that rather quickly after such a conflagration, the roots of tenacious plants whose visible growth had been burned off sped the production of new shoots, thousands of them, and these were the finest food the mammoths ever found. What was even more important, ashes from the great fires fertilized the ground, making it more nutritious and more friable, so that young trees would grow with a vigor they would not otherwise have known. One of the best things that could happen to the Mammoth Steppe, with its mixture of trees and grass, was to have a periodic fire of great dimension, for grasses, shrubs, trees and animals prospered in its aftermath.
It was puzzling that something as dangerous as fire, which Matriarch had barely escaped many times, should be the agency whereby she and her successors would grow strong. She did not try to solve this riddle; she protected herself from the dangers and luxuriated in the rewards.
In these years some mammoths elected to return to the Asia they had known in their early years, but Matriarch had no inclination to join them. The Alaska that she now knew so well was a congenial place she had made her own. To leave would be unthinkable.
But in her fiftieth year changes began to occur that sent tremors, vague intimations, to her minute brain, and instinct warned her that these changes not only were irreversible but also cautioned that the time was approaching when she would have to wander off, leaving her family behind, as she sought some quiet place to die. She had, of course, no sense of death, no comprehension that life ended, no premonition that she must one day abandon her family and the steppes on which she found such ease. But mammoths did die, and in doing so they followed an ancient ritual that commanded them to move apart, as if they were symbolically turning over to their successors the familiar steppe and its rivers and its willow trees.
What had happened to signal this new awareness? Like other mammoths, Matriarch had been supplied at birth with a complex dental system that would provide her, over the long span of her life, with twelve enormous flat composite teeth in each jaw. These twenty-four teeth did not appear in a mammoth’s mouth all at one time, but this posed no difficulty; each tooth was so large that even one pair was adequate for chewing. At times there were as m
any as three pairs of these huge things, and then chewing capacity was immense. But as the years passed, each tooth moved inexorably forward in the jaw until it actually fell from the mouth. When only the last two matching teeth remained in position, the mammoth sensed its days were numbered, because when the last pair was lost, continued life on the steppe would be impossible.
Matriarch now had four big matching pairs, but since she could feel them moving forward, she was aware that her time was limited.
When the mating season began, bulls from far distances started to arrive, but the old bull who had broken Matriarch’s right tusk was still so powerful a fighter that he succeeded, as in past years, in defending his claim on her daughters. He had not, of course, returned to this family year after year, but on various occasions he had come back, more to a familiar area than to a particular group of females.
This year his courtship of Matriarch’s daughters was a perfunctory affair, but his effect upon the older child of the younger daughter, a sturdy young bull but not yet mature enough to strike out on his own, was remarkable, for the young fellow, watching the robust performance of the old bull, felt vague stirrings. One morning, when the old bull was attending to a young female not of Matriarch’s family, this young bull, unexpectedly and without any premeditation, made a lunge for her, whereupon the old bull fell into a rage and chastised the young upstart unmercifully, butting and slamming him with those horns that crossed at the tips.
Matriarch, seeing this and not entirely aware of what had occasioned the outburst, dashed once again at the old bull, but this time he repelled her easily, knocking her aside so that he could continue his courtship of the heifer. In time he left the herd, his duty done, and disappeared as always into the low hills fronting the glacier. He would be seen no more for ten months, but he left behind him not only six pregnant cows but also a very perplexed young bull, who within the year should be doing his own courting. However, long before this could take place, the young bull wandered into a stand of aspen trees near the great river, where one of the last sabertoothed cats to survive in Alaska waited in the crotch of a large tree, and when the bull came within reach, the cat leaped down upon him, sinking its scimitar teeth deep into his neck.