Alaska (3 page)

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As the nine mastodons entered Alaska they faced four radically different types of terrain, varying somewhat from the land they had left behind in Asia. At the farthest north, facing the Arctic Ocean, lay a thin strip of arctic desert, a bleak and terrifying land of shifting sands on which little that was edible grew. During the dozen winter weeks when no sun appeared, it was covered by thin snow that did not pile up into high drifts but was whipped by intense winds across the barren landscape until it came to rest in low drifts behind some ridge or rock.

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 be careful to escape 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 amidst 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 17

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 largesse of the new woodland and the more controlled but assured 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 in almost to his knees.

Now he slipped and sloshed his way through the watery tundra, fighting off the myriad of 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 in 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 at 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 effect of the waning sun was the more important impulse, 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 which assured an ample food supply.

His first half-year in Alaska had been a spectacular success, but 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 18

alone in their favorable habitat, for a most varied menagerie had preceded them in their exit from the Asian mainland, and one cold morning when he stood alone in 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 frightful upper teeth almost three feet long and incredibly sharp. Mastodon knew that though this sabertooth 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 forward and expect to impale his adversary on them; they were not intended for that purpose. But his tiny brain did send signals which 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, and although the blow did not send the cat spinning or in any way immobilize it, it did divert the attack and it did cause a bruise which infuriated the sabertooth without disarming him.

So 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 which 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, scraped under a set of low branches, and had the cat not wisely jumped free, it would have been crushed, which was what Mastodon 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 19

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 and protesting, 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 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 what nature intended them to be: great cats with remarkable hunting abilities.

Like the sabertooth, 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 Asia. 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 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 sabertooth 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.

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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 a foothold on 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 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 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 congenial.

A CURIOUS PHYSICAL CONDITION LIMITED THE MOVEMENT

of animals in Alaska, for Beringia's land bridge could exist only when the polar ice caps were so extensive that they imprisoned vast quantities of water which had previously sustained the oceans. Indeed, the prime requisite for the existence of the bridge was that the ice sheets be immense.

However, when they were, they crept across western Canada, and although they never reached Alaska in an unbroken mass, they did send forth probing glaciers, and in time these frozen fingers reached right down to the Pacific shoreline, forming a set of icy barriers which proved impassable to animals and men. Alaska was then easy to enter from Asia, impossible to leave for the interior of North America. Functionally, Alaska became a part of Asia, and so it would remain during vast periods.

At no time that we are aware of could any animal or man cross the bridge and proceed directly to the interior of North America; but since we know that eventual passage did occur, for mastodons, bison and sheep did move from Asia into mainland North America, as did men, we must conclude that such movement came only after an extended waiting period in Alaska's ice castle.

Proof of this can be found in varied data. Certain animals 21

that came into Alaska remained there, while their brothers and sisters wandered on to the rest of North America during some interval when the barriers were removed.

But the two strains became so totally separated when the barriers closed that over the thousands of years that they remained apart they each developed unique characteristics.

The movement of animals across the bridge was by no means always in one direction, for although it is true that the more spectacular beasts mastodon, sabertooth, rhinoceros came out of Asia to enrich the new world, other animals like the camel originated in America and carried their wonderful capacities into Asia. And the intercontinental exchange which had the most remarkable consequences also moved westward across the bridge and into Asia.

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 ponderous feet.

They were sleek creatures, swift of movement, alert of eye, and he watched with ordinary animal interest and inspection 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, stare at him, and pass on.

They were horses, the new world's beautiful 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 exquisite 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.