Fauna Series No. 3

Fauna of the National Parks — No. 3 Birds and Mammals of Mount McKinley National Park

Mammals

DESCRIPTIONS OF MAMMAL SPECIES

ALASKA MOOSE
Alces gigas [MILLER]

GENERAL APPEARANCE.—The moose is the largest member of the deer family and the Alaska species is the largest of all the moose. The bull moose has wide-spreading, heavy, palmated antlers which are grown and shed each year; the females lack these appendages. Moose of both sexes have long legs and chunky bodies. The height of the animal at the shoulders is greater than is the height at the rump. This, combined with the broad muzzle and the pendulous growth of skin and long hair hanging from the throat, gives the moose a grotesque appearance. The general color of the Alaska moose is dark brown. The coat of the calf is a rich reddish-brown, and it is not spotted as is the coat of the young deer. Length 108 inches; tail, 2.5 inches; hind foot, 31 inches.

IDENTIFICATION.—The high shoulders, large size, dark coloration—in the field these animals often appear to be almost black—"hooked" nose and pendant strip of skin, called a "bell", which hangs from the throat, are all good field characters of the moose. The tracks of this animal are like gigantic deer tracks. They are broad at the base and taper to a sharp point at the toe; they are not rounded and cowlike as are the tracks of the caribou.

DISTRIBUTION.—Moose were formerly found in timbered areas over most of the northern half of North America. During the summer in Mount McKinley National Park moose are usually found in or along the margin of the spruce timber. They may be found at times in the willow thickets or even in the higher passes while traveling from one forested area to another. They seek the willow thickets above timber in order to escape the swarms of mosquitoes and moose flies which are more numerous in the lowlands. These insect pests directly affect the local distribution of both caribou and moose.

HABITS.—On the divide at the head of Caribou Creek, July 9, 1926, we encountered a cow moose with her calf in a dense thicket of willows that averaged 5 feet in height. On May 25, 1932, Chief Ranger Louis Corbly found a cow moose with her newly born calf which was so young that it was not yet able to walk. The parent moose, having a strong maternal instinct, chased the man away. When on foot Corbly attempted to make a close inspection of the moose's calf. Fortunately for the ranger, however, his saddled horse stood nearby and he was able to escape the attack made by the infuriated cow moose. I experienced a similar surprise attack by a moose. She undertook to defend her recently born calf near Telegraph Creek in British Columbia. One cannot be too cautious in approaching the new born young of any species, but visitors to Mount McKinley National Park should be especially careful in approaching young moose or any cow moose with young.

On July 22, 1926, at Double Mountain we watched a cow moose crossing a high mountain pass. She traveled at a slashing trot and covered a mile in 10 minutes. Her gait was normal and undisturbed, for we were sitting quietly and she did not see us.

During the summer of 1932, at a small lake near the mouth of Igloo Creek, a cow moose and her twin calves were observed many times. This moose became so accustomed to automobiles passing on the highway that she paid little attention to them, even though the cars often stopped long enough to secure photographs. However, she was quite shy when approached by a man on foot. Tracks along the muddy margins of the lake and cropped-leaf plants showed that this mother moose was in the habit of feeding upon the aquatic vegetation which grew in the shallow lake.

In Mount McKinley National Park the antlers of the bull moose begin to branch by the first of June. A bull moose killed by Charles Sheldon on July 29, 1906, at the north base of Denali had antlers which were about grown but still in the velvet. They had a spread of 67 inches. If these antlers had been allowed to mature the moose doubtless would have carried a record head. By the first of September the velvet covering of antlers is rubbed off and the antlers are grown and hardened. The bull cleans and polishes his antlers by rubbing them against the brush and the hard bark of trees. By the last of September the rutting season is at its height. On December 19, 1907, near Peters Glacier, Charles Sheldon killed a bull moose that had already shed his antlers. This was unusual, for the antlers are not dropped ordinarily until after Christmas.

Sheldon states that during the summer the moose eat considerable green grass and buds of willows. During the winter he found them feeding exclusively on willows.

Moose are excellent swimmers. Charles Sheldon witnessed a cow and her calf swim across a lake at Cathedral Mountain on September 8, 1907.

In winter moose are prone to make a network of beaten trails in the snow, usually in timber near a suitable food supply. This "yarding" gives them a chance to move about freely and to obtain food. It also gives them a better opportunity to protect themselves against the attack of wolves. However, when the snowfall is excessive, as it was in the winter and spring of 1932, many of the moose leave the lowlands and seek the higher wind blown ridges where there is less snow. At such times, in traveling through the crusted snow the skin on the legs of the moose is often cut through and the animal leaves a bloody trail behind him. One of the McKinley rangers reported a narrow escape which he had when he suddenly came upon a moose. This animal was plowing through the deep crusted snow. The moose, feeling cornered, evidently considered the man's approach an attack; he charged at the ranger, who was on snowshoes, and the man was barely able to escape.

Moose are increasing and are now quite common in Mount McKinley National Park.

STONE'S CARIBOU
Rangifer arcticus stonei [ALLEN]

GENERAL APPEARANCE.—With the exception of the Alaska moose, the caribou is the largest member of the deer family found within the park. In Alaska everyone refers to the males as "bulls"; to the females as "cows"; and to the young as "calves." An average sized caribou bull stands 50 inches in height at the shoulders and weighs, when in fair flesh, more than 300 pounds. They have longer legs but are not so chunky as are the mountain sheep. In the late fall the bulls are usually dark brown, often having a white mantle that covers the neck and shoulders. During the winter this white area often extends back along the sides giving the appearance of a broad white patch. Caribou are the only members of the deer family in which both the males and females bear antlers. The antlers of the caribou are shed annually. These antlers are large, wide-spreading and have numerous points (fig. 64), some of which are much flattened, especially the large brow tines or shovels which extend well forward over the nose. The ears of the caribou are of medium size, dark colored, and well covered with fur. The tail is short and thickly covered with hair; it is brown above and white beneath. The hoofs are dark brown, rounded, and cowlike, but are more flexible and better adapted to pawing in snow.

Length, 84 inches; tail, 6 inches; hind foot, 24 inches.

Figure 64.—Antlers of two fighting Stone's caribou bulls which became interlocked with fatal results.
Photograph taken July 16, 1926, Sanctuary River. J. S. D. No. 2

IDENTIFICATION.—In the field in summer the caribou may be distinguished at a distance from their usual associates, the mountain sheep, by the fact that they are dark colored while the sheep appear entirely white. When close at hand, the large upright many-branched antlers serve to identify these animals. Caribou have a characteristic way of running together into a compact band when alarmed (fig. 65). On scenting danger the tail is raised, the white under portion serving as an effective danger signal to the remainder of the herd. When alarmed the animals dash off with a comical leap and a characteristic stiff-legged gallop.

Figure 65.—A band of Stone's caribou, scenting danger.
Photograph taken June 3, 1926, Savage River. M. V. Z. No. 4952.

DISTRIBUTION.—Caribou range over most of the barren ground or tundra regions along the Arctic coast of North America. They are common in Mount McKinley Park and are found in summer chiefly on the rolling tundra and along the higher grass-covered ridges above timber line (fig. 66). The head of Savage River, Double Mountain, and Sable and Highway Passes are localities where caribou may be found in numbers during the summer season. However, these animals are of a roving disposition and while hundreds may be present in a locality one day, they may be gone the next day.

Figure 66.—A group of about 500 Stone's caribou on summer range. Note old caribou trails above the herd.
Photograph taken July 10, 1932, East Fork. W. L. D. No. 2664.

HABITS.—The caribou is a Stone Age animal. The stone carvings which have come down to us as the very earliest graphic record of man in Europe depict the caribou in its characteristic and unmistakable form. So far as we have been able to see, there has been no change in the general appearance of the animal during thousands of years.

There is considerable seasonal and daily movement of caribou in the McKinley region. During the annual rutting season in the fall, there is evidence that the caribou near the north base of Mount McKinley band together in herds, as many as three or four thousand being observed in one aggregation, and travel in a general northerly direction. The herds circle about, but finally reach their wintering grounds along the lower foothills and plains well outside the mountains along the northern boundary of the park. They drift eastward during the winter and reenter the park along the Teklanika and Sanctuary Rivers the following spring. Caribou were noted returning westward in the park on May 19, 1926. On this date seven caribou were observed traveling along a ridge near Jenny Creek. They seldom stopped to feed but maintained an average speed of 3 miles per hour and were obviously in transit, traveling to their high summer range (fig. 66).

Caribou may be encountered singly or in herds of several thousands. Ordinarily during the summer small bands of from 30 to several hundred individuals are met with most frequently. On July 9, 1926, at Double Mountain, on the divide between the Sanctuary and Teklanika Rivers we counted more than 200 caribou that were scattered about through the pass and well up on the mountain slopes. At Sable Pass on the day following we found evidence, tracks, and trampled herbage, that an immense herd of caribou, estimated at 5,000, had passed through that region 3 or 4 days previously. However, the herd had traveled on and we saw only half a dozen stragglers. On July 19, at McKinley Bar, we encountered a band of 12 caribou cows and 8 calves. At the head of Savage River on June 28 we found a herd of 53 caribou feeding in a meadow about 100 acres in extent. There were about an equal number of each sex in this herd and a good many calves. Single individuals or small bands of 3 or 4 were encountered almost daily during our stay in the park. At Igloo Creek on July 21, 1932, a band of caribou consisting of 347 individuals, by actual count, was observed.

In summer the caribou occupy the open tundra and higher grassy slopes. We found that there was a general tendency to follow the fresh new vegetation up the mountain slopes as the season advanced. Visits to the head of Savage River and to Highway Pass during June and July revealed from one to several herds of caribou standing or bedded down on the snowbanks (fig. 67) to escape the attacks of flies and mosquitoes. These two localities and Sable Pass are among the best and most accessible places for park visitors to see, study, and enjoy caribou.

Figure 67.—Stone's caribou regularly resort to snowbanks to escape attacks of mosquitoes and flies.
Photograph taken July 8, 1932, Stony Creek. W. L. D. No. 2656.

The eyesight of caribou during the summer is anything but keen. We took occasion to prove this fact many times. On May 20, 1932, while climbing a steep hillside near the Savage River bridge, we sat down on a bare rock slide to rest. Looking up we beheld a band of migrating caribou approaching. They were headed straight for us. We knew that we were within a few feet of the regular caribou trail but we remained quietly seated in order to see how close they would come. When the main band had approached within 40 yards, they stopped and began to graze. The old bull caribou which was leading the band came straight on toward us and passed quietly within 10 feet of our resting place on the open hillside. The wind had been blowing directly from the feeding animals and in our direction, but as soon as the old bull leader reached a point behind us he got our scent and nearly exploded in his frightened attempt to escape the previously unobserved danger. Upon seeing their leader excited, the whole band turned and bolted up the hill. They plunged into the snowdrifts, their legs sinking in the soft snow clear up to their bodies.

Again, on June 28, 1926, I crawled along a bare, open, rocky slope to within a hundred yards of a band of caribou without being detected. Then I slid slowly down the steep slope, keeping close to the ground, until I approached to within 30 yards of two large bull caribou that were lying in the open in plain sight. These two bulls did not pay the slightest attention to me as long as I made no violent motions and remained crouched on the ground. At various times during the summer we found that if the wind were favorable it was possible, by lying down on the ground, to slide downhill slowly into the very midst of a band of grazing caribou.

Investigation has shown that the caribou's sense of smell is as good as its eyesight is poor. On one occasion, a cow caribou winded us while we were yet over a half-mile distant. At another time a band of caribou caught our scent, borne to them by a favorable wind, nearly a mile from where we stood. The following incident is indicative of this animal's keen sense of smell. On June 27, at the head of Savage River, we crawled up a bare, gravel slope in an endeavor to get close to a band of caribou. Some time later, the same band crossed our trail which was then almost an hour old. The moment they caught the human scent of our tracks 8 out of the 12 suddenly stopped and started back.

On another occasion a band of about 40 caribou came down off the hill and grazed along a bench above the river. Taking the camera and keeping to the windward of the caribou I crawled up behind a row of dwarf willows close to the animals. They were about 200 yards distant and were grazing directly toward me, the wind being from them. Some of the old bulls had beams 30 inches long and although nearly grown the heavy antlers were still in the velvet. The animals grazed up to within 100 yards of me then turned back, and lying down, began to chew their cuds. Soon it started to rain and the wind shifted. It carried a light breeze from me toward the caribou and within 10 seconds, the whole herd was on its feet (fig. 65). They threw their heads up in order to catch any scent that might be carried by the air currents. Observation with binoculars showed that their nostrils dilated as they sniffed the air suspiciously. One more whiff and they were off, circling around above me they galloped downward in a close-packed herd. I remained hidden all this time behind the willows so that they could not see me. It was a clear case of their ability to detect human presence through the acuteness of their sense of smell.

Caribou are as keen to scent danger as mountain sheep are to see it. It is interesting that the caribou roaming over the relatively flat country should have developed a wonderful sense of smell and that the mountain sheep inhabiting the rocky areas should have developed extremely keen sight. It is true that the continual winds of the level or rolling tundra are almost sure to bring the scent of an enemy to the caribou, while the broken air currents of the rugged mountainous country that the sheep inhabit are less depend able. Because of the nature of the topography and of their vantage points at high elevation, the sheep have evidently learned to depend on their eyesight to warn them of danger.

It was our experience that the female caribou were much more alert and much quicker to detect the presence of danger than were the males. This fact was impressed upon our minds many times during the summer. Invariably, when we crawled up to a band of caribou, it was the females and especially the females with young who first detected our presence. For example, on June 28 we crawled up towards a herd of caribou. When we got within 60 yards of a cow and calf she saw us and, apparently being fearful for her calf, moved off. A large, dark-colored bull caribou was lying down contentedly chewing his cud. When we approached to within 40 yards of him a cow that was with the bull saw us and began to edge away. After the cow had left I crawled down to within 30 yards of four old bulls that were drowsily feeding out in the open (fig. 68). Many times in Alaska I have observed that the leader of a band of caribou is usually some old female (fig. 69).

Figure 68.—Four old male Stone's caribou feeding on an open hillside.
Photograph taken June 28, 1926, head of Savage River. M. V. Z. No. 4970.

Figure 69.—An old female led the herd of Stone's caribou. Note cow with small calf at right.
Photograph taken June 27, 1926, head of Savage River. M. V. Z. No. 4963.

Aside from heavy breathing and snorting, the caribou utter a peculiar grunt which reminds one of the muffled barking of a small dog. The calves when separated from their mothers utter a series of these sounds. Though muffled, on a calm day, these sounds will carry for a quarter of a mile. Even when separated from her calf, a mother caribou will make no effort to warn it or to coax it back by any audible call.

Tracks of a large bull caribou made in the sand measured 5 inches in width. Other tracks made in firm wet soil (fig. 70) were also 5 inches in width. From measurements taken of tracks made by a number of large males we found they were all about the same size. Tracks of female caribou were found to vary from 4 to 4-1/2 inches in width, being approximately as long as they were wide. In both sexes the tracks are very much like cow tracks in outline (fig. 70).

Figure 70.—This typical track of a mature male Stone's caribou was like a cow track in outline and measured 5 inches in width.
Photograph taken June 30, 1926, Savage River. M. V. Z. No. 4955.

Figure 71.—That Stone's caribou sometimes travel singly is indicated by these individual tracks in deep snow. Photograph taken May 29, 1932, Jenny Creek. W. L. D. No. 2977.

When undisturbed, caribou often travel in single file (fig. 71). Trails thus formed are a conspicuous feature of the landscape. They average about 14 to 18 inches in width, and in some places the soil has been cut down to a depth of as much as 2 feet by the recurrent travel of generations of caribou. On the soft, springy tundra trails are usually mere depressions from 4 to 6 inches in depth.

The droppings of caribou are similar to those of deer, except that they are much larger, longer, and somewhat more pointed.

Caribou are prone to visit mineral springs or "licks" during the summer. On the trail between Double Mountain and Igloo Creek there is a well-established mineral spring which is visited by large numbers of caribou during the summer. Here we found a muddy area nearly 100 feet square that had been trampled bare of all vegetation by the caribou. We found that a few of these animals visited the lick at the head of Ewe Creek; however, this particular spring was visited especially by mountain sheep.

The spring molt in males was much in evidence by June 27. By that date the caribou's pelage had become ragged, the dark new summer pelage showing through the old, faded, winter coat in large patches, particularly about the head and shoulders. At this time the cows were in somewhat better pelage than were their mates, the old hair being more "shed out." The new hair continues to grow until by late fall the pelage consists of long, coarse, brown and whitish hairs which are longer and harsher than were those of the short, soft, brown summer coat.

We had been accustomed to think of caribou as living almost, or entirely, on reindeer or caribou moss and lichens (fig. 72) and were therefore surprised to find that during the summer the caribou lived to a considerable extent on succulent green vegetation, such as Boykinia (fig. 73), and on browse. Although we watched them at close range for many hours, we did not at any time during June and July see them feeding on reindeer moss which could easily have been obtained. In grazing they were found to eat most of the available green vegetation. A number of them were observed to browse extensively on green willows. This had been observed also by Charles Sheldon who found the stomach contents of two caribou, shot by him on November 23, 1907, to contain willow buds.

Figure 72.—Caribou moss and alpine willow (here shown natural size) are extensively utilized as food by Stone's caribou in the fall. Photograph taken June 17, 1926, Savage River. M. V. Z. No. 4992.

Figure 73.—Boykinia richardsonii gray, one of the succulent herbs that form the major part of the caribou's food in summer. Photograph taken July 14, 1926, north base of Mount McKinley. M V. Z. No. 4991.

On July 10, 1926, at Double Mountain, we observed a band of caribou feeding. By 9 o'clock in the evening most of the caribou had eaten their fill and were lying down chewing their cuds. There was a chill wind blowing through the pass which gave them relief from the flies and mosquitoes. The mountain sheep feed less hurriedly and were still grazing assiduously at 10 o'clock in the evening. As has been stated, caribou are often found in close association with mountain sheep. We frequently found the two species grazing side by side within 10 feet of each other without the least show of animosity, although there must be considerable competition at times for food.

On July 22, a large moose was observed as it traveled hurriedly along a caribou trail in the pass at Double Mountain. However; the animal did not pause to feed until it was well down the slope and near timber. Twice during the summer we found reindeer, or hybrids between reindeer and caribou, mingling with the wild caribou in the park. Thus, on May 23, 1926, in Savage River Canyon, there was one small spotted reindeer in a band of 26 caribou, it had escaped apparently from a neighboring herd and had joined the caribou. Again, on June 27, at the head of Savage River, a spotted animal was closely observed which had every appearance of being a cross between a reindeer and a caribou. He was too large to have been a full-blooded reindeer. Several reindeer "escapes" have been known to run with caribou in the park. The Superintendent of Mount McKinley National Park told us that in order to keep the native caribou stock pure the rangers had been instructed to shoot such stray or feral reindeer whenever they were seen within the park area.

By the time we arrived in the park on May 19, the antlers of the male caribou had reached a length of several inches. There was, however, considerable variation in antler development. Although the antlers of the bulls were nearly grown by June 27, on this same date it was observed that the antlers of cows accompanied by small calves were only 4 inches long and that they were much smaller than those of the cows without calves. In general, the antlers of the female develop later in the season than do the antlers of the male, and there is a corresponding difference in the time of shedding. On November 23, 1907, Charles Sheldon killed a bull caribou that had just shed its antlers. The pedicels were still bloody. This was unusual, for ordinarily the bulls do not shed their antlers at such an early date. It has been claimed that the late shedding of antlers in the female is due to her greater need of protection for herself and her young. None of the female antlers which we saw were as large as those of an average bull's. However, on November 24, 1907, Charles Sheldon killed a large caribou cow that had antlers which measured 51 inches in length.

From early June until about the first of September the bulls remain up near the source of the rivers in the main range, feeding on grass and other plants during the day and resting at night. About the first of September most of the bull caribou leave the high country and go north, down to the adjacent treeless country where they herd the cows. Since the species is polygamous there are many combats among the rival bulls. The rut or breeding season begins in September and by September 20 most of the old bulls have swollen necks and a strong musky odor which is characteristic of the breeding male.

Only one calf is born per cow during a season. We saw no instance of twins. By actual count, only about half of the females were found to have calves by the last of June. On July 21, 1932, at Igloo Creek I counted a band of 63 caribou which consisted of 40 cows, 20 calves, and 3 young bulls. In some instances the calves may have died, but every indication seemed to lead to the conclusion that possibly not more than two-thirds of the females bear young each season. The calves are dropped during the latter part of May. The first one which we saw was found on May 28, 1926. This calf was obviously only a day or two old. It was barely able to walk and could not stand on its wobbly legs for any length of time. The calves at birth are not spotted, as are the young of must of the deer family. The young of this species are lighter in color than are the adults. In general appearance, a month-old caribou calf is very similar in color, size, and contour to the calf of an ordinary Jersey cow. Caribou calves appear to have little affection or attachment for their mothers and often wander aimlessly about. It was no uncommon sight to see a mother caribou following, instead of leading, her calf. On one occasion we watched a lone calf that was rushing up and down hill and over ridges in a seemingly senseless fashion. At length he ceased running, lay down on a mossy knoll, and went to sleep. The young caribou develop slowly. The yearlings are not more than half the size of a full-grown cow. A newly born mountain sheep keeps close within the protection of cliffs and does not stray far from its mother. In marked contrast to this, the young caribou wanders far from home and seemingly depends upon its mother to hunt it up. Charles Sheldon has pointed out that the cows constantly lose their young and run about excitedly trying to find them. It is not improbable that the infant mortality is much higher in the case of caribou than it is in mountain sheep.

During the rut it is not unusual to find clumps of willows or lone spruce saplings which have been defoliated, or even broken down, by the males rubbing their antlers against the branches in order to remove the velvet. The caribou bulls are known to fight viciously among themselves, particularly at the beginning of the rutting season. On July 16, 1926, near the Sanctuary River, we found the white, bleached bones and interlocked antlers of two large bulls that had succumbed in a battle for supremacy. Their antlers had become so locked in fighting that the animals had been unable to free themselves and had died of exhaustion and starvation. Judging from the antlers, this fight had transpired some time during the previous fall. Pieces of hide were still in evidence about the carcasses. One set of antlers had a spread of 41 inches and the other nearly 44 inches. The height above the skull of the larger antlers was 43 inches. The horns were locked in three places (fig. 64), and although two men pulled as hard as they could they were unable to separate the two heads. Foxes and magpies had fed on the carcasses of the fallen monarchs, as was evinced by numerous droppings near the bones. The skeletons showed they had fought so viciously that the shoulder blade of one bull had been punctured by the tine, or sharp tip, of the other's horns.

The large timber wolves follow the caribou bands and exact a daily toll. However, the wolves tend to weed out the weaklings. This practice of the wolves is one of nature's methods of keeping the caribou herds physically fit. It is a natural process and has existed for thousands of years.

The introduction of domestic reindeer offers serious complications to the welfare of the native caribou, both through the introduction of disease and through breeding of the strong native caribou with the weaker and smaller domestic reindeer. The crossing of the inferior reindeer with the caribou endangers the perpetuation not only of the caribou in Mount McKinley Park but the magnificent herds throughout interior Alaska. Where the two animals occupy the same range, the caribou is doomed to disappear and the resulting population will be a mongrel mixture. Since reindeer and caribou cannot exist together, it would be wise to restrict the territory occupied by the reindeer in such a way that the caribou may be preserved.

Owing to the transient nature of the species it is exceedingly difficult to get any satisfactory count or census of the entire caribou population. However, by going over certain typical sections of their range and by making careful counts in 1926 and again on the same areas in 1932, we feel confident that there has been no serious loss in the total caribou population of the park during that time.

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