Since none of his breed could survive long in this desert, Mastodon intuitively shied away from the far north, and this left him three other areas to explore that were more rewarding. Just south of the desert and blending into it in various ways stretched another relatively narrow strip, a tundra, perpetually frozen twelve to twenty-four inches below the surface but rich in rooted plant life when the topsoil was dry enough to permit growth. Here succulent lichens abounded and mosses rich in nutrients and even an occasional low shrub with branches stout enough to provide leaves for grazing. No real trees grew here, of course, for summers were too short to permit flowering or adequate branch development, and this meant that whereas Mastodon and his family could eat well on the tundra during the long summers when nearly perpetual daylight spurred plant growth, they had to make sure they escaped it when winter approached.
That left two rich areas between the northern and southern glaciers, and the first of these was a splendid, hospitable region, the great Alaskan steppe, an area of rich grass growing high most years and yielding some food even in poor years. Large trees did not customarily grow on the steppe, but in a few secluded spots that were protected from searing winds, clusters of low shrubs gained a foothold, especially the dwarf willow whose leaves Mastodon loved to crop. When he was especially hungry he liked to rip off the bark of the willow with his strong tusks, and sometimes he would stand for hours amid a group of willows, browsing and eating a sliver of bark and striving to find among the low branches a bit of shade to protect himself from the intense heat of summer.
The fourth area he had at his disposal was larger than any of the previous three, for in these years Alaska had a predominantly benign climate, which both allowed and encouraged the growth of trees in regions that had previously been denuded and would be again when temperatures lowered. Now poplar, birch, pine and larch flourished, with woodland animals like the spotted skunk sharing the forests with Mastodon, who relished the trees because he could stand upright and nibble at their copious leaves. After feeding, he could use the sturdy trunks of the pine or larch as convenient poles against which to scrape his back.
So between the largess of the new woodland and the more controlled and dependable richness of the steppe, Mastodon and his family could eat well, and since it was spring when they entered Alaska, he naturally headed for a region like the one he had known well in Siberia, the tundra, where he was certain that low shrubs and grasses waited. But now he faced an interesting problem, for the sun’s heat that had enabled these plants to grow also melted the top eight or ten inches of the permafrost, turning the softening soil into a kind of sticky mush. Obviously, there was nowhere for the moisture to escape; the earth below was frozen solid and would remain so for countless years. As summer approached, thousands of shallow lakes thawed, and the mush thickened until at times Mastodon sank almost to his knees.
Now he slipped and sloshed his way through the watery tundra, fighting off the myriad mosquitoes that hatched at this time to torment any moving thing. Sometimes, when he lifted one of his huge legs out of the swampy mess into which it had slowly sunk, the sound of the leg breaking free from the suction echoed for long distances.
Mastodon and his group grazed on the tundra during most of that first summer, but as the waning heat of the sun signaled the approach of winter, he began drifting gradually south toward the waiting steppe, where there would be reassuring grass poking through the thin snow. During the early days of autumn, when he was in the dividing line between tundra and steppe, it was almost as if the shrub willows that now appeared low on the horizon were calling him to a safer winter home, but the waning sun exerted a stronger influence, so that by the time the first snows appeared in the area between the great glaciers, he and his family had moved into the forested area that assured an ample food supply.
His first half-year in Alaska had been a spectacular success. Of course he was not aware that he had made the transition from Asia to North America; all he had done was follow an improved food supply. Indeed, he had not left Asia, for those solid sheets of ice to the east had made Alaska in those years a part of the larger continent.
As the first winter progressed, Mastodon became aware that he and the other mastodons were by no means alone in their favorable habitat, for a most varied menagerie had preceded them in their exit from the Asian mainland. One cold morning when he stood alone in the soft snow, cropping twig ends from a convenient willow, he heard a rustle that disturbed him. Prudently, he withdrew lest some enemy leap upon him from a hiding place high in the trees, and he was not a moment too soon, for as he turned away from the willow he saw emerging from the protection of a nearby copse his most fearsome enemy.
It was a kind of tiger, with powerful claws and a pair of upper teeth almost three feet long and incredibly sharp. Mastodon knew that though this sabertoothed tiger could not drive those fearsome teeth through the heavy skin of his protected rear or sides, it could, if it obtained a secure foothold on his back, sink them into the softer skin at the base of his neck. He had only a moment to defend himself from this hungry enemy, and with an agility that was surprising for an animal so big, he pivoted on his left front foot, swung his massive body in a half-circle, and faced the charging sabertooth.
Mastodon had his long tusks, of course, but he could not lunge and impale his adversary on them; they were not intended for that purpose. But his tiny brain did send signals that set the tusks in wide sweeping motions, and as the cat sprang, hoping to evade them, the right tusk, swinging with tremendous force, caught the rear legs of the sabertooth. Although the blow did not send the cat spinning or in any way immobilize him, it did divert the attack by inflicting a minor wound.
The cat stumbled among the trees, then regained control, and circled swiftly so that it could attack from the rear, hoping with a giant leap to land upon Mastodon’s back, from where the vulnerable neck could be punctured. The cat was much quicker than the mastodon, and after a series of feints that tired the larger animal as he tried to counter them, the sabertooth did land with a mighty bound, not on the flat of the back, where it wanted to be, but half on the back, half on the side. It struggled for a moment to climb to a secure position, but in that time Mastodon, with a remarkable instinct for self-preservation, moved under a set of low branches, and had the cat not wisely jumped free, it would have been crushed, as Mastodon had intended.
Repelled twice, the great cat, some nine times larger than the tiger we know today, growled furiously, lurked among the trees, and gathered strength for a final attack. This time, with a leap more powerful than before, it came at Mastodon from the side, but the huge animal was prepared, and pivoting again on his left front foot, he swung his tusks in a wide arc that caught the sabertooth in midair and sent it sprawling back among the trees, one of its legs painfully damaged.
That was enough for the sabertooth. Growling, it slunk away, having learned that if it wanted to feast on Mastodon, it must hunt in pairs, or even threes or fours, because one wily mastodon was fully capable of protecting itself.
Alaska at this time contained many lions, huge and much hairier than the kind that would come later. These possessed no handsome manes or wavy tails, and the males lacked the regal quality that would someday be such a distinguishing characteristic. They were simply what nature intended them to be: great cats with remarkable hunting abilities. Like the sabertooths, they had learned never to attack a mastodon singly, but a hungry pride of six or seven could badger him to death, so Mastodon never intruded upon areas where a number of lions might be hiding. Rocky tors covered with trees, deep vales from whose sides groups of lions might attack, these he avoided, and sometimes as he plowed noisily along, bending young and scattered trees to his will, he would see a group of lions in the distance feeding upon some animal they had run to earth, and he would change direction lest he attract their attention.
The water animal with which Mastodon occasionally came into contact was the massive beaver, which had followed him out of A
sia. Of giant size and with teeth that could fell a large tree, these beavers spent their working hours building dams, which Mastodon often saw from a distance, but when work was done the great beasts, their heavy fur glistening in the cold sunlight, liked to play at rowdy games, and their agility differed so markedly from the ponderous movements of Mastodon that he was amazed at their antics. He never had the occasion to live in close contact with the underwater beavers, but he noticed them with perplexity when they gamboled after work.
Mastodon had his major contacts with the numerous steppe bison, the huge progenitors of the buffalo. These shaggy beasts, heads low and powerful horns parallel to the ground, grazed in many of the areas he liked to roam, and sometimes so many bison collected in one meadow that the land seemed covered with them. They would all be grazing, heads pointed in the same direction, when a sabertoothed tiger would begin stalking a laggard. Then, at some signal Mastodon could not detect, the hundreds of giant bison would start running away from the terrible fangs of the cat, and the steppe would thunder with their passage.
Occasionally he encountered camels. Tall, awkward beasts who cropped the tops of trees, they seemed to fit in nowhere, moving slowly about, kicking ferociously at enemies, and surrendering quickly whenever a sabertooth managed to cling to their backs. At rare times Mastodon and a pair of camels would feed in the same area, but the two animals, so vastly different, ignored each other, and it might be months before Mastodon saw another camel. They were mysterious creatures and he was content to leave them alone.
In this placid, ponderous way, Mastodon lived out his uneventful life. If he successfully defended himself against sabertooths, and avoided falling into bogs from which he could not scramble free, and fled from the great fires set by lightning, he had little to fear. Food was plentiful. He was still young enough to attract and hold females. And the seasons were not too hot and moist in summer or too cold and dry in winter. He had a good life and he stumbled his gigantic way through it with dignity and gentleness. Other animals like wolves and sabertooths sought sometimes to kill him for food, but he hungered only for enough grass and tender leaves, of which he consumed about six hundred pounds a day. He was of all Alaska’s inhabitants in these early years the most affable.
One morning as Mastodon browsed among cottonwood trees near the edge of a swamp in central Alaska, he saw approaching from the south a line of animals much smaller than he had ever seen before. Like him, they walked on four feet, but unlike him, they had no tusks, no heavy covering of hair, no massive head or bulky feet. They were sleek creatures, swift of movement, alert of eye, and he watched with interest and attention as they approached. Not a single gesture, not one movement gave him any indication that they might be dangerous, so he allowed them to come near, stop and stare at him before passing on.
They were horses, the new world’s wonderful gift to the old, and they were on their wandering way into Asia, from where their descendants, thousands of years later, would fan out miraculously to all parts of Europe. How beautiful they were that morning as they passed Mastodon, pressing their way into the heartland of Alaska, where they would find a halting place on their long pilgrimage.
Nowhere else could the subtle relationships of nature be so intimately observed. Ice high, oceans low. Bridge open, passageway closed. The ponderous mastodon lumbering toward North America, the delicate horse moving toward Asia. Mastodon lurching toward inescapable extinction. The horse galloping to an enlarged life in France and Arabia. Alaska, its extremities girt in ice, served as a way station for all the travelers, regardless of the direction in which they headed. Its broad valleys that were free of ice and its invigorating climate provided a hospitable resting place.
MATRIARCH, THE WOOLLY MAMMOTH
How sad it is to realize that most of the imposing animals that lingered in Alaska during the last ice age and its intervals of temperate climate passed into extinction, usually before the appearance of man. The great mastodons vanished, the fierce sabertoothed tigers disappeared in mists that enclosed the bogs at whose edges they hunted. The rhinoceros flourished for a while, but then waddled slowly into oblivion. The lions could find no permanent niche in North America, and even the camel failed to flourish in its land of origin. How much more interesting North America would be if we had retained these great beasts to enliven the landscape, but it was fated not to be. They rested in Alaska for a while, then vanished from the Americas.
Some of the immigrants did adjust, and their continued presence has made our land a livelier place: the beaver, the caribou, the stately moose, the bison and the sheep. But there was another splendid animal that crossed the bridge from Asia, and it survived long enough to coexist with man. It had a fighting chance to escape extinction, and the manner in which it fought that battle is an epic of the animal kingdom.
The woolly mammoth came out of Asia much later than the mastodon. It arrived at a time of sharp transition when a relatively mild interval was ending and a harsher one beginning, but it adjusted so easily to its new environment that it thrived and multiplied, becoming one of the most successful examples of immigration and the archetypal Alaskan animal of this distant period.
Its remote ancestors had lived in tropical Africa, elephants of enormous size with long tusks and huge ears, which they flapped constantly, using them as fans to keep their body temperature down. In Africa they browsed on low trees and pulled grass with their prehensile trunks. Admirably constructed for life in a tropical setting, they were magnificent beasts.
When such elephants moved slowly north they gradually converted themselves into creatures almost ideally suited to life in the high Arctic zones. For example, their ears diminished in size to about one twelfth of what they had been in the tropics, for now the animals did not require fanning to enable them to live in great heat; they needed minimum exposure to the Arctic winds that drained away their heat. They also rid themselves of the smooth skin that had helped them keep cool in Africa, developing instead a thick covering of hair whose individual strands could be as long as forty inches; when they had been in the colder climates for several thousand years, they were so covered with this hair that they looked like unkempt walking blankets.
But not even that was enough to protect them from the icy blasts of winter in Alaska—especially during the time we are now considering, when the incursion of ice was at its maximum—so the mammoth, already covered with thick, protective hair, developed an invisible undergrowth of thick wool that augmented the hair so effectively that the animal could withstand incredibly low temperatures.
Internally, also, the mammoth changed. Its stomach adjusted to the different food supply of Beringia, the low, tough grasses, wonderfully nutritious when compared with the huge loose leafage of the African trees. Its bones grew smaller, so that the average mammoth, markedly smaller than the elephant, would expose less of its body to the cold. Its forequarters became much heavier than its hind parts and more elevated, so that it began to show a profile less like an elephant’s and more like a hyena’s, high in front, tapering off at the back.
In some ways the most dramatic change, but not the most functional, was what happened to its tusks. In Africa they had grown out of its upper jaw in roughly parallel form, curved downward before straightening out. They were formidable weapons and were used when males contested for the right to keep females in their group. They were also useful in bending branches lower for browsing.
In Arctic lands the tusks of the mammoth underwent spectacular change. For one thing, they became much larger than those of the African elephant, for in some cases they measured more than twelve feet in length. But what made them distinctive was that after starting straight forward and down, like the elephant’s, they suddenly swept outward, far from the body, and down in a handsome sweep. Had they continued in this direction, they would have been enormous and powerful weapons for attack or defense, but what happened was that they arbitrarily swung back toward the central axis, until at last their tips met and somet
imes actually crossed, far in front of the mammoth’s face. This bizarre condition served no constructive purpose. Indeed, the tusks hampered feeding in summer, but in winter they did have a minimal utility, for they could be used to sweep away snowdrifts so that mosses and lichens hiding below could be exposed for eating. Other animals—the bison, for example—achieved the same result by merely pushing their big heads into the snow and swinging them from side to side.
Protected against the bitter cold of winter and enjoying the plentiful forage of summer, the mammoth proliferated and dominated the landscape long after the much larger mastodon had vanished. Like all other animals of the early period, the mastodon had been subject to attack by the ferocious sabertooth, but with the gradual extinction of that killer, the mammoth’s only enemies were the lions and wolves that tried to steal young calves. Of course, when a mammoth grew old and feeble, packs of wolves could successfully chivy it to death, but that was of no consequence, for if death had not come in that manner, it would have in some other way.
Mammoths lived to fifty or sixty years, with an occasional tough customer surviving into its seventies, and to a marked degree it was the way the animal died that has accounted for its fame. On numerous occasions in Siberia, Alaska, and Canada—so numerous that statistical studies can be made—mammoths of both sexes and all ages stumbled into boggy pits, where they perished, or were overcome by sudden floods bearing gravel, or died on the banks of rivers into which they fell.
If these accidental deaths occurred in spring or summer, predators, especially ravens, quickly disposed of the cadavers, leaving behind only stripped bones and perhaps long strings of hair, which soon vanished. Accumulations of such bones and tusks have been found in various places and have proved helpful in reconstructing what we know about the mammoth.