NATIONAL PARK SERVICE Fauna of the National Parks of the United States No. 5 The Wolves of Mount McKinley

Description

THE CARIBOU is a circumpolar deer adapted to life in the Arctic. Both sexes carry antlers. The cow's antlers are small and branching, those of the bull large and picturesque with a well-developed brow tine extending over the nose from the base of one or both antlers. The blunt, curved hoofs provide a broad support for walking on the tundra or in snow. The long, thick coat of the bulls is dark brown, contrasting conspicuously with the pure white neck and mane and white stripe along the flank. The cows are similarly colored but the white is duller and the coat in general paler.

The shoulder height varies from 46 to 55 inches. The average dressed weight of 18 bulls, according to O. J. Murie (1935, p. 13), was 247 pounds, the heaviest 305 pounds. Of 6 adult bulls the average live weight was 366 pounds. The dressed weight of 12 adult cows averaged 148 pounds, and the average live weight of 5 adult cows was 213 pounds. A male calf taken by O. J. Murie in September weighed 75 pounds dressed, another 121 pounds live weight.

The caribou is a gregarious animal usually found in large herds. Sometimes the herds contain seven thousand or more animals, but a few hundred is the usual number. On the move much of the time, the caribou make extensive migrations which involve hundreds of miles of travel. The migrations follow general route patterns over a period of years, but have many variations and sometimes there are drastic changes. After passing over certain areas for a number of years, the animals may shift their ranges to entirely new areas. This migratory habit and the shifting of ranges are highly beneficial to the vegetation in that they tend to lighten use and give the forage plants opportunity for recovery. This is especially beneficial to the lichens (favorite caribou food) which recover slowly after being overgrazed.

According to O. J. Murie (1935), there are five principal caribou herds in Alaska, each of which is segregated sufficiently to be considered as a unit. There is, no doubt, some intermingling of animals from different herds. The animals in Mount McKinley National Park form a well-defined group, occupying a range which centers in the park and vicinity. They range over a region at least 300 or 400 miles in diameter; the exact limits are not known. At times this herd probably has some contact with the Yukon-Tanana herd which is the largest group. The total number of caribou in Alaska 20 years ago was estimated at more than a million. So far as known the status of the herds has not changed greatly since that time. However, there has been considerable hunting in recent years and the wolf population has been greater so that there may have been some decrease in late years. The park herd, numbering 20,000 to 30,000, constitutes only a small part of Alaska's caribou population.

Classification

The Alaska caribou have all been placed in the "Barren Ground group." Two subspecies have been recognized—Rangifer arcticus granti, to which the caribou on the Alaska Peninsula have been referred, and Rangifer arcticus stonei which includes all the other caribou in Alaska (O. J. Murie, 1935). There is great individual variation in antler form which has often given the impression that the woodland and Barren Ground caribou are both found in interior Alaska.

Numbers

During the 5 days between June 28 and July 2, 1941, about 14,685 adults and 6,900 calves were seen within the park, or a total of more than 21,000 caribou. There was not much possibility of duplication but no doubt some nocturnal migrants were missed. It is not known what part of the herd this count represents. The main bands of bulls, which had already moved west of Wonder Lake, were missed, and there no doubt were others which were scattered about to the west and elsewhere. It is safe to say that the Mount McKinley National Park herd numbers between 20,000 and 30,000.

Movements of Mount McKinley National Park Caribou

BRIEF SURVEY OF MOVEMENTS FROM 1925 TO 1941

Detailed information on the movements of the Mount McKinley National Park caribou herds is lacking, but there is enough information in the Park Superintendents' monthly reports to give an approximate idea of the annual movements. There are, of course, many gaps in our knowledge since much of the territory used by caribou is not easily accessible and is infrequently visited by man. I have reviewed the monthly reports of the Superintendents and summarized the information contained therein. An understanding of the movements of the caribou is important from the standpoint of the park visitors because so often they are disappointed at failing to see the animals, which at the time of their visit may have moved beyond the region accessible by road. For the benefit of future workers in this area, and to place on record facts that may prove of value in further studies of caribou wanderings, the data are given here in some detail.

1926.—In the winter of 1925—26, 2,000 or more caribou wintered in the region around Toklat River and McKinley Fork, but there were few in the eastern section, including the area between Teklanika River and Park Headquarters. Apparently they had been wintering to some extent along the north boundary. Many at this time had been wintering in the Broad Pass region along the railroad, but there is no mention of any migration to this area. In 1922 and 1923 O. J. Murie and I observed an eastern migration in the fall between Savage River and Park Headquarters.

In July 1926, six or seven thousand caribou were found in the Toklat River region, and hundreds were found at the head of Savage River. In August they were reported to have gone westward.

In October 1926, there was a general migration from the western part of the park, over Sanctuary Pass to Windy and points east in the Broad Pass area. But there was also a large herd in the general area west of Stony Creek and a few stragglers wintered at Savage. Apparently the main herd had split in two, some wintering east of the park and some in the western part. There is no report of the return of the caribou from the Broad Pass region. They probably dribbled westward inconspicuously.

1927.—In July 1927, several thousand were reported in the East Fork and Toklat River sections. In October 1927, six or seven thousand caribou again moved out of the park through the Windy region to Broad Pass. This migration was not noticed on the north side of the main range but it was thought that these caribou did come from the north side. In December 1927, 1,500 were reported in the Kantishna region and there were other signs of large herds moving east along the northern boundary. Large numbers seen on both sides of the Tanana River were thought to have come from the park herd.

1928.—In February 1928, a herd of 1,000 caribou entered the park near Cantwell, moving west, and in March other herds followed. They were seen over much of the park in March. In June large herds were reported in the Clearwater Creek region south of McKinley Fork. The report stated that tourists were obliged to travel beyond Copper Mountain if they wished to see the large herds in summer. In August bands near Wonder Lake were starting eastward, and in September several small herds were seen in the eastern section of the park. In October several thousand caribou traveled eastward across the Teklanika River and over to Windy and into the Broad Pass area. About 1,000 were reported wintering near Windy. It was reported that most of the caribou went 40 miles down the Kantishna River to winter. About 200 wintered near Savage River.

1929.—In May and June caribou were reported plentiful in the park, especially in the western section south of McKinley Fork. In September thousands headed south past Windy.

1930.—In October a scarcity of caribou in the park occurred but thousands were reported in the Valdez Creek area east of Windy. The migration to this area escaped observation. In December about 5,000 were reported passing through the central part of the park.

1931.—In April the caribou returned to the park, traveling west, and many were reported present in summer. In the winter of 1931—32 there was apparently no migration to the Broad Pass region. Thousands were reported wintering in the Lake Minchumina region to the northwest.

1932.—In May caribou were reported returning to the park from the west and they were common in June. In November there were few caribou in the park but they moved in from the west in December, and 3,000 were estimated to be wintering in the eastern section.

1933.—The caribou were abundant in the eastern part of the park from December to August, when they moved westward. In November there were few caribou in the park. At this time they were reported abundant near Lignite, 25 miles north of the park and along the railroad. Some wintered along the north boundary.

1934.—In June, 10,000 caribou were estimated in the eastern part of the park. A few animals wintered near Savage River in 1934—35.

1935.—In April large bands returned to the Wonder Lake section, presumably from the west or north and by May were ranging as far east as Savage River. In July approximately 5,000 caribou were seen in Sable Pass. In August they were scarce from Toklat to Park Headquarters. Notes are meager, but apparently few caribou were in the park in the winter of 1935—36.

1936.—No caribou were seen in May but in June it was estimated that there were 25,000 between Igloo Creek and Mile 72. In July only a few were seen.

1937.—In the winter of 1936—37 few caribou were found in the park. None was reported in May, but in June 2,000 were seen between Igloo Creek and Toklat River. In July it was estimated that there were 25,000 within the park boundaries. In August the migration had passed and only a few scattered ones were seen. During the fall caribou were scarce in the park.

1938.—During the winter of 1937—38 a few caribou wintered at Savage River. Large herds were reported in the Kantishna area. Former Chief Ranger Corbley saw 500 on McKinley Fork bar in March. Many caribou were seen in the Wonder Lake area in April. In May, Ranger Rumohr reported 20,000 in the Kantishna region. During June bands of 20 to 200 were seen along the highway. In early July many migrated westward from Sable Pass. By August the caribou had gone to the west, and during the fall few were seen from the highway. It was estimated that from 1,500 to 2,000 wintered in the Savage and Sanctuary River regions, and that 10,000 wintered between McKinley Fork and Herron Creek.

1939.—In the summer caribou were abundant in the park in May, June, and early July, and then they moved westward. Presumably they wintered west of Wonder Lake.

1940.—In May caribou returned to the eastern section of the park and were plentiful in June and early July. In September there were many near Wonder Lake and along the north boundary.

1941.—Many caribou spent the winter along the north boundary and west of Wonder Lake. They were abundant in the park in May and June.

WINTER MOVEMENTS

From 1922 to 1931 a large part of the caribou herd moved over the Alaska Range in the fall and wintered in the Broad Pass region. Since 1933 the records indicate that the main herds have wintered in the Lake Minchumina area northwest of Wonder Lake and along the north boundary of the park. I am told that prior to 1935 about 1,000 caribou wintered on lower Savage River along the north boundary but that for a few years thereafter they were scarce. The number wintering within the park between Savage and Sanctuary Rivers has varied considerably. During the winters of 1935—36, 1936—37, and 1937—38 very few stayed here. In 1938—39 two or three thousand wintered in this region; in 1939—40 there were scarcely any, but in 1940—41 caribou were again wintering here. Although the main herds may winter in relatively small areas, smaller groups sometimes are rather widely distributed. Thus each year certain minor and major variations may occur.

SUMMER MOVEMENTS

For short periods in spring and summer large herds of caribou may be seen passing through the park, but within a few days the scene may change from one of abundance to scarcity. In the years that the caribou were wintering in the Broad Pass area there was a spring and fall period of abundance between Wonder Lake and Savage River. In the spring the caribou passed through the park going westward; in the fall they passed through it going eastward.

In recent years many of the caribou have come from the west in May and June and apparently crossed the Alaska Range at the head of Sanctuary River. Some caribou may cross the Range from Muldrow Glacier and eastward. In 1939, for instance, tracks were noted at Muldrow Glacier and as far west as McGonnagal Pass. In a few weeks they have recrossed the range and again traveled to the west.

Data gathered from the monthly reports of the Park Superintendents show that caribou have been abundant in the park east of Wonder Lake during the following months:

1926—July, October
1927—July, October
1928—March, October
1929—May, June, September
1930—No data
1931—April, May, June, July
1932—May, June
1933—January to August
1934—June
1935—April, May, June, July
1936—June
1937—June, July
1938—April, May, June, July
1939—May, June, early July
1940—May, June, early July
1941—May, June, early July

1939 MOVEMENTS

I observed the caribou movements in 1939, 1940, and 1941 so can describe them in more detail than was possible for the earlier years. In 1939 the estimated 2,000 caribou wintering between Savage and Sanctuary Rivers had moved north early in April. South of Wonder Lake many caribou were calving in May. Small bunches moved eastward so that in late May and early June a few scattered animals were encountered as far east as Sanctuary and Teklanika Rivers. The main bands remained in the vicinity of the calving grounds for a few weeks The first large bands moving eastward were seen in Sable Pass on June 12. A thousand caribou, mainly cows and calves, were observed. They were moving along steadily. On June 13 one band in Sable Pass contained 800 adults and about 400 calves. Between the north side of Cathedral Mountain and Teklanika River about 800 cows and calves were seen moving south. They had come through passes north of Sable Pass. On June 14 about 1,500 of them were seen in Sable Pass and north of the road along the Toklat River. On June 16 about 3,500 were seen at the Teklanika Forks. These were traveling in bands of from 100 to 250 which consisted mainly of cows and calves with a few bulls. Another 700 were seen traveling along the base of Double Mountain, making a total of 4,200 caribou for the day.

On June 17 about 2,000 were seen at Teklanika Forks; on the 18th about 500; and on the 19th about 400. These caribou were traveling steadily. All the bands seemed to go 6 or 7 miles up the west branch of Teklanika River to the glaciers, back to the Forks and up the east branch and back to Double Mountain, where they crossed to Sanctuary River. On June 20, 200 were seen on Cathedral Mountain, 100 on Teklanika River, and 400 on Toklat River above the road. By June 22 the main herds of cows and calves and some bulls had passed eastward to Sanctuary River, up which they traveled, presumably crossing to the south slope of the Alaska Range. A trapper told me that for several seasons large bands of caribou had come in June to the Chulitna River on the south side of the Alaska Range and disappeared after spending about 2 weeks there. That information is in harmony with the data on migration as observed in the park, for after the caribou have gone east they soon are seen returning and going west.

Apparently the herds made up mainly of bulls, and a few herds of cows, did not make the long migration up Sanctuary River. On June 24 more than 1,000 caribou, mainly old and young bulls, were reported on McKinley Fork bar going west. On June 25 a band of 48, mainly bulls, was noted at Copper River bar, and at Stony Creek 45, mainly bulls, were traveling west. On June 27, on Sable Pass, a band of 50 bulls and another of 60 cows and calves were moving west. On June 30 about 500, mainly bulls, came up Teklanika River. It appeared that some hands consisting largely of bulls had moved eastward near the north boundary, most of them going only to Teklanika River, then had circled south toward Sable Pass and upper East Fork River, and then had turned west again. On July 2 about 2,700 caribou, including many calves, were seen on Copper River bar. I do not know where these caribou came from but it seemed likely that they had gone up Sanctuary River and recrossed the Alaska Range on the upper Toklat River or at some other place along the Range, possibly Anderson Pass. Most of these seemed to have recrossed the Range between Toklat River and Anderson Pass since few were seen east of Toklat River in the westward migration.

A few small bands were seen dribbling westward in early July, and on July 13 a band of 800 was seen at Toklat River going west. On July 16 a band of 149 and another of 125 were on Sable Pass moving west. A large band was seen on Stony Creek. After this date only a few odd animals were seen. The caribou remained scarce east of Wonder Lake up to the middle of October, when I made my last observations that year.

1940 MOVEMENTS

In the winter of 1939—40 caribou were scarce in the park, at least between Park Headquarters and Wonder Lake. No data are available on where they wintered but presumably it was to the west, possibly in the Lake Minchumina region.

On May 6 at McKinley Fork near the highway about 100 caribou were seen and many tracks showed that some had come down on McKinley Fork bar from the west. On May 9 a number of caribou were noted on the bar just south of Teklanika River Canyon. They were coming over the mountain from the Sushana watershed to the northwest. From the top of the mountain to the bar there was a line of caribou coming down the steep slope. When I was forced to leave, the caribou were still streaming over the top of the mountain. In the afternoon when I returned they were spread out over the tundra between Teklanika and Sanctuary Rivers and moving south. I do not know how many there were in the herd. They apparently continued to pass this point for several days.

On May 11 a band of 100 was moving east on Sable Pass. Between May 9 and the last of the month there were several hundred between Teklanika and Savage Rivers. They kept moving southward. Large bands moved up the Teklanika River and Igloo Creek and went west over Sable Pass. Many of these animals seemed to have come from the north boundary in the general region of the Sushana and Teklanika Rivers and moved south to Sable Pass, then traveled westward. Others went up Sanctuary River and perhaps crossed the Alaska Range before traveling westward.

From May 29 to July 2 about 12,000 adult caribou were seen traveling west between Sable Pass and Toklat River. Some which came from upper Sanctuary River no doubt included those that had come into the Teklanika River region on May 9 and later. Others came up the Teklanika from the north and turned west at Sable Pass and at passes to the north of Sable. Some came up East Fork River from the north and turned west just south of the highway. During July and August very few caribou were seen. In September the caribou reappeared in the Wonder Lake region. On September 6, I saw about 500 near Wonder Lake and about 500 on McKinley River bars. There were large herds north of Wonder Lake in the Kantishna region at this time. In October many of them worked east along the north boundary, almost to the railroad.

During the winter of 1940—41, beginning in October, many caribou were found on both sides of the north boundary of the park. One trapper said the caribou had come to Lignite and to Dry Creek near the railroad on the north boundary. Lee Swisher, trapping on the Teklanika and Sushana Rivers, estimated four or five thousand caribou wintering in that region. In traveling along the north boundary from Savage River to Wonder Lake in January I saw many caribou tracks on both sides of the boundary. On the return trip, no caribou sign was noted between Mile 70 and Mile 27 on the highway. A few were found between Savage and Sanctuary Rivers along the highway.

1941 MOVEMENTS

During March and April bands totaling two and three hundred caribou were seen near the road at Savage River, but early in May few remained.

On May 14 large bands of caribou came into Sanctuary River Valley from the northwest. A ranger reported seeing 2,000 that day. The following day I saw but 600 in the same locality, indicating that they were moving southward. On May 18 there were about 1,000 animals east of Savage River and south of the road. On May 28, on the rolling hills between Savage and Sanctuary Rivers south of the road, there were about 6,000 adult caribou and 3,000 calves. During the next 2 or 3 days they kept moving southward up Sanctuary River Valley. On June 3 about 350 were seen, mainly far up Sanctuary. After that only scattered ones were seen between Savage and Sanctuary Rivers.

On June 4 about 250 caribou in small bands of a dozen or less traveled to Copper River bar from the north. These caribou were mainly old and young bulls and yearlings; no calves were among them. On June 5 a band of 150 cows with calves was traveling south along Igloo Creek, coming up from Teklanika River. Between June 6 and June 9, small bands of bulls were seen between Sable Pass and Mile 74. They seemed to be dribbling in from the north, probably coming from the region along the north boundary. On June 9 a band of 60 cows and 10 calves was seen on Stony Creek traveling east and two other bands of cows at Mile 69 and Mile 40 were going east. At this time all bulls were traveling west.

Between June 10 and June 26 few caribou were seen. But on the evening of June 27 a party reported seeing a band of 4,000 on Stony Creek traveling west. The following day I saw about 4,000 adult caribou at Mile 70, about 1,000 on Copper River bar, 600 at Stony Creek, 700 at Toklat River, and 200 others along the way. The adults were largely cows. Usually the calves were not counted because when the caribou are traveling in big bands or lying down in the distance it is difficult to count the calves. Samples were counted which indicated that about half the cows were followed by calves. There were approximately 6,500 adult caribou and perhaps about 3,000 calves. These animals were traveling hurriedly. On June 29 I counted about 3,000 adults. In these bands there were probably from 1,000 to 1,500 calves. On June 30 I saw a band of about 2,000 adults and perhaps 1,000 calves, and other bands totaling 1,750 adults and 800 calves. On July 1, I saw a total of 875 adults and 400 calves. On July 2 about 560 adults and 200 calves were counted. I was unable to count caribou from July 3 to 5 because of floods washing out and blocking the roads. Only a few were seen on the 6th; 70 were seen on the 7th. Apparently the main run had lasted about 5 days. Between July 3 and July 22 very few were seen. Then on July 24 about 1,500 were seen going north from McKinley Bar toward the north boundary. Those that had gone west were now moving back east a short distance, thence northward. My observations were discontinued August 4.

Trails

Wherever the caribou migrate they leave many parallel trails, for the large herds often travel on a broad front. In some places there may be a hundred or more trails only 2 or 3 feet apart. Not nearly all the trails are used each year and they may be in disuse for a period of years. Most trails in Mount McKinley National Park lead east and west along the migration route but many also follow the rivers in a north-and-south direction. The trails tend to follow the contours, but in many places they ascend and descend steep slopes, and may go over mountains.

Food Habits of Caribou

The caribou is a grazing and browsing animal with a special fondness for lichens. The more important foods eaten in the Mount McKinley region consist of lichens, grasses, willows, and dwarf Arctic birch.

WINTER FOOD

Although lichens, and to a lesser extent mosses, are relished at all times of the year, they are especially sought during the period when the abundance of green foods of summer are not available. My summer observations in Mount McKinley National Park indicate that relatively few lichens are eaten. Perhaps more are eaten at this season farther westward where such food is in greater abundance. In September, when the green vegetation has largely disappeared, caribou seek out and feed extensively on lichens. Species of the genus Cladonia seem to be the favorite ones. Throughout the winter, the caribou paw through the snow for lichens as well as grasses. One of the requirements of a wintering ground seems to be the presence of lichens, even though they by no means form the exclusive diet.

Grasses, sedges, and willows are also eaten extensively in winter. Even patches of coarse sedge were closely grazed in some places. So far as I could tell, practically all species of grasses and sedges were utilized. The willow twigs are eaten and some of the dry leaves are picked off the ground. Willow was much utilized during the winter months.

SUMMER FOOD

The important summer foods are grasses and sedges, willows, and dwarf birch, supplemented by an assortment of herbs. In early spring the caribou near Wonder Lake were seeking the new green shoots of sedge and grass. Grasses and sedges form a large part of the summer food. When the willows and the dwarf birch leaf out in May they are eaten in large quantities. For a period in May and early June willow and dwarf birch seem to make up the bulk of the food. The leaves are stripped from the twigs, and some of the fine twigs are also eaten at this time of the year, perhaps more or less accidentally. Where large bands of caribou have fed, many of the willow twigs which have had the leaves removed are withered. Several kinds of willows are eaten, including two or three species of dwarf willow that are highly palatable. More than half the stomach contents of a cow which died July 15 consisted of two species of dwarf willow. Willows and dwarf Arctic birch are widely distributed and abundant in the park.

Various herbs such as Boykinia, Hedysarum, and Dryas are eaten in summer. Hedysarum, growing abundantly on the gravel bars, is eagerly sought, so that where herds of caribou have passed, hardly a plant has escaped a close grazing. Equisetum was especially sought on several occasions. (For a large list of food plants see O. J. Murie, 1935.)

When migrating a caribou may settle down for a period to feed, but much of the time it eats hurriedly as it travels. Often, before a willow twig is stripped of leaves, the caribou has moved forward and is reaching far back to complete the action. Even when the caribou has settled down to feed more leisurely, it faces in the direction it is going. This is so consistently true that one can almost always know the direction of the general migration of a herd by watching the movements of a single animal. When the animals are on the wintering grounds or on the calving grounds they feed more leisurely, although even then they are usually moving about a great deal.

Stomach contents of some dead caribou found on the range were as follows:

Rutting Period

The rutting period begins some time after the middle of September and continues to the latter part of October. On September 14, 1940, two bulls were seen paying attention to cows, but most of the bulls seen were not yet with the females. On October 7, 1940, four small bands were seen, each with a bull in charge. Three of the bands consisted of 11, 4, and 13 cows, and in each band there were two calves. The fourth band was larger than the others but no count was obtained. During the rutting period the old bulls lose the large amount of fat accumulated during the summer period and face the winter in a gaunt condition. The fact that bulls have used up so much reserve energy during the rutting period may have a bearing on their survival through the winter months.

Caribou Calves

DESCRIPTION

The newborn caribou calf is reddish-brown, with a strip of black sometimes 3 or 4 inches wide running down the middle of the back. Some calves are more red than others. They lack the spots found in deer and elk. The blunt, squared-off muzzle is black. A few days after birth the pelage becomes a faded brown. The bulk of the calves are rather uniformly colored, but variations are fairly common. One calf was a bright orange color. Another was exceptionally whitish, and it was significant that the mother of this one was also unusually light colored. The first coat is lost in July, the change taking place first on the face. On July 13 several calves were noted which had lost most of the first coat and had acquired the new pelage which at first appeared almost black. This pelage soon becomes similar to that of the adult, but the white on the necks and sides is absent the first year.

A female calf born on May 18, 1940, had the following measurements: total length, 32 inches; tail length, 3-3/4 inches; hind leg, 14 inches; ear, 3 inches ; shoulder height (from tip of hoof), 24 inches. Another newborn calf was 22 inches high at the shoulders.

The calves have a deep guttural, short call, reminding one of the quality in the bullfrog's note or the deep grunt of a pig. The calves are often quite noisy, especially in a moving herd or in a herd that has been disturbed. A single calf is the rule, no twins having been observed.

CALVING

The calving period is roughly from the middle of May to the middle of June. In 1940 the first calf was seen on May 12, and in 1941 on May 14. Most of the calves were born during the following 2 weeks. The latest record I have is for June 22 when a calf only a day or two old was seen.

Figure 48: A calf caribou less than a day old. Note the black, square muzzle. [May 24, 1939.]

To give birth to their calves, cows generally wander off varying distances from the main herds. At this time a lone cow is almost sure to be near a newborn calf. Generally these lone cows still carry one or both antlers. Within a few days the cows with their calves join the main herds. Sometimes the mothers band together in groups of a dozen or so, and move about together for a short period.

The open rolling tundra in the region about McKinley, Cache, and Clearwater Rivers is often referred to as a favorite calving ground. The caribou calved in that region in 1939, but in 1940 and 1941 most of the calving took place on the gently rolling tundra between Savage and Sanctuary Rivers. Possibly the location of the principal calving grounds depends largely on where the caribou happen to be at the time. The fact that the same areas are used several years for calving may simply mean that the general movements of the herds are similar for those years.

In 1940 large herds of caribou first moved into the calving area between Teklanika and Savage Rivers on May 9. Large bands were last seen in this region on May 29. Most of the caribou had left before the 29th and had moved southward toward the head of Sanctuary River. In 1941 large bands moved into this same region on May 14. Some calved on the north side of the outside range and moved into the area later. On May 28, bands totaling 6,000 animals, not including calves, were seen moving southward between Sanctuary and Savage Rivers. On May 29 about 2,000 adult caribou with calves were seen in the region, and on May 30 only about 100 adults with calves were noted. There is some movement of the herds before all the calves are born, but for the most part during this period there seems to be an interval when the herds wander about locally.

The calves are unusually precocious. On May 17, 1940, I found a calf in a spot which I had passed about 3 hours before, so that it was known to be not more than 3 hours old. There was a packed-down area in the snow about 12 feet across, and a little blood was noted in two places. The calf's legs were still moist. It managed to stand up with considerable effort and after walking a few steps in the snow it fell down. It tried walking several times, seeming to gain additional strength with each effort until finally it was able to follow me around, which it insisted on doing. It gave the typical guttural grunt. While I was with the calf the mother circled about 200 yards away.

The behavior of this calf was similar to that of a number of other newly born calves which were observed. I was unable to check closely on a calf's development, but in a day or two they can follow the mother, and I would guess that in about a week or 10 days they are able to run almost as fast a their mothers. On June 1, I saw calves, chased by a wolf, keeping up with the cows. Most of these calves were not more than 2 weeks old.

RELATION OF CALVES TO COWS

I found no indication of cows leaving their calves while going off to feed, as do antelope, deer, and moose. From the time the calf is born it remains close to the mother. When able to follow readily, the calf as a rule remains close beside or behind the mother like a shadow. This close attachment, is important from the standpoint of survival in a herd animal, for a great many calves would otherwise lose their mothers. Some observers have stated that the calves seem to have little attachment for their mothers and wander off at random. After watching thousands of calves my impression is that the calves do remarkably well in remaining close to their mothers. It is true that when a large herd has been disturbed a few calves become separated, but with several hundred animals milling around it is surprising that more of them are not left astray. On several occasions I have seen cows and calves searching for one another.

On May 29, 1941, I observed an interesting incident in this connection. On the rolling tundra between Savage and Sanctuary Rivers I saw a band of about 700 adult caribou with calves moving westward and then circling northward. They had moved away from two grizzly bears. After the caribou had moved a little less than a mile, I noticed that two calves were lost, a half mile from the main herds. One calf joined up with a cow and calf and followed in their wake for some distance, and then moved off in another direction, obviously searching for its mother, which in the meantime had returned from the main herd and soon found her calf. When the mother came the youngster at once commenced to nurse vigorously. It had been lost at least a half hour. The other calf wandered toward the herd, started for several cows, then circled back toward the place it had left. It then disappeared in a swale and was not seen again. This calf was searching for its mother, and after following the herd had returned to where it apparently had last seen her. A cow, probably the mother of the second calf, was searching but while I watched she did not go back far enough to find the calf.

On July 1, 1940, a lone calf came running in my direction and stopped within 15 yards of me. It apparently was looking for its mother and came to investigate me. It later crossed some broad gravel bars and found her.

The cows are reasonably solicitous when their young are in apparent or real danger. On May 24, 1939, I approached a cow with a calf that was less than a day old. When the cow ran off the calf followed slowly. Part of the time the mother trotted slowly enough for the calf to keep up, even though I was hurrying after them about 75 yards behind. Each time the mother found herself a short distance ahead, as happened four or five times, she returned and nuzzled the calf. When it finally lay down, the cow stopped about 50 yards away and did not run off until I captured the calf. Then she ran over a nearby rise and circled above me, keeping watch from a distance of about a half mile until I left. This mother seemed more solicitous than a mother elk would be.

On May 24 two rangers and I chased a calf which was following a cow slowly. When one of the rangers overtook the youngster, the mother, a short distance ahead, turned and showed her defiance by pawing the air. After they ran off we caught up to another cow and calf and both calves dropped in the brush when they were unable to keep going. The mothers peered anxiously at us from the steep slope opposite. After going over the hill one of the cows returned and came within 75 yards as we were departing. Some cows run off more readily than others, often disappearing after a brief show of solicitude. Quite often they return to peer over a hilltop to see if the intruder has gone.

Figure 49: A mother caribou trots slowly so her newborn calf can keep up with her. [McKinley River, May 24, 1939.]

On occasions when wolves have killed a calf I have seen the mother searching the area for it. Once I observed a cow smelling of her calf at least several hours after it had been killed. On one occasion a cow with a calf too young to follow, ran off with the herd, but returned to the calf in 10 minutes.

The calves soon begin to feed on green food so that by the time they are a month old their main food is vegetation. On June 12 the calves were feeding extensively on vegetation. The stomach contents of a calf found dead on June 14, 1939, was well filled with green food including the twig of a willow. Since the bulk of the food of very young calves is vegetation, the weaning would not seem to have much effect on the physiology of the calves. By fall the bodies have become accustomed to being nourished almost entirely by vegetation which, we can assume, furnishes a balanced ration. I do not know how late the calves continue to nurse. A cow killed by O. J. Murie on October 18, 1922, had considerable milk in the udder so that the calves were apparently getting some milk at that time.

Parasites

Two parasites—the warble fly (Oedemagena tarandi) and the nostril fly (Cephanomyia nasalis)—annoy the caribou considerably and at times, perhaps, are a serious drain on their vitality. O.J. Murie (1935, p. 10) writes as follows about these parasites:

The warble fly deposits its eggs on the hair of caribou; the larvae hatch, home through the skin, and migrate to the back region, where they develop just under the skin, until they finally work out and drop to the ground, producing the familiar perforated skin condition. in July and August, the active egg-laying time, these flies cause the caribou much uneasiness. Although the fly does not sting, the animals fear them and stand in a strained, alert attitude, stamping a foot or shaking the head when one hovers about. It would be interesting to know to what extent the animal is able to avoid these attacks by such vigilance. The writer has seen a caribou suddenly run for more than a quarter of a mile, then abruptly drop on a sand bar, in the shelter of a steep bank, and remain there quietly for a long time. Such flight is probably effective, if long enough and in the right quarter of the wind, for the flies probably hunt by scent.

On one occasion, while traveling overland with a companion, using several dogs as pack animals, the writer noticed a warble fly buzzing along behind the dogs, flying along until it caught up with the rear dog, but not alighting. Presently the fly seemed to become fatigued and lit on the ground. When the dogs were some distance ahead the fly again took up the chase and soon was hovering about the dog once more. This procedure continued for some time, leaving the impression that the fly was fatigued each time it dropped to the ground, and that after a period of rest it again followed the scent of the animals. In the absence of caribou, the fly probably was somewhat attracted by the scent of the dogs but not to the extent of laying eggs.

The nostril fly deposits its larvae in the nostrils of the caribou, and they finally lodge in the soft palate, in the posterior part of the mouth cavity. In spring they become very noticeable and appear as a tightly packed wad of larvae, the writer in one case having counted 125 in the throat of one animal. In April caribou were seen coughing repeatedly for some time, apparently as a result of such irritation. The larvae drop out probably in May.

On July 30, 1939, I watched a yearling for half an hour, alternately holding its head in a clump of willows and biting at flies. At times it cocked its ears and appeared to be watching a fly in front of it. It frequently licked its hind leg near the ankle, and several times a front foot and a hind foot. Occasionally it shook itself. Sometimes the nose was held almost touching the ground. This caribou seemed to be endeavoring to avoid warble flies and possibly nostril flies too. Such behavior was seen several times.

The animals would sometimes bunch up on the river bars. After reading what Sdobnikov (1935 p. 64) says about this habit in reindeer, it appears that the caribou may avoid warble flies by standing close together. He states that "in order to lessen the injury to the reindeer, caused by the gadfly [warble fly], the experienced herder puts the herd on 'tandara'." The term "tandara" means a place where the herd is kept closely together during the flight of the warble fly. There the herd stands sometimes for from 8 to 10 hours. The animals in the center of the band are scarcely molested.

If the caribou should become too abundant in a region these two parasites might become so numerous and infest the caribou to an extent that would greatly reduce their vitality. The shifting of the ranges and movement of the caribou probably reduces the degree to which they are affected by the parasites. Exceptionally heavily infested animals would presumably become weakened and more subject to predation and disease. Sdobnikov (1935) states that in Russia the warble fly may utterly exhaust the reindeer when the infestation is heavy. More than 1,000 larvae have been found on one animal.

The bladderworm (Taenia hydatigena) is found in the liver. Another tapeworm (T. echinococcus), becomes encysted in the lungs, and a hair lungworm has been found in the lung. The protozoan Sarcosporidia was found in one caribou by Hadwen and Palmer (1922). It produced a "pitted" appearance on the surface of various bones and tendons. The incidence of these parasites in caribou is not yet well known.

Disease

The Park Superintendent's report for January 1926 speaks of the presence of a disease among the caribou the previous year as follows: "No indications of disease have manifested themselves of late, and much to the relief of all concerned, there does not seem to be any further advancement of the ailment which killed a number of caribou last year." I have found no other mention of this "disease" so do not know its nature or how large the losses were.

Several skulls that were picked up showed severe necrosis and exostosis of the jawbones, especially around the teeth. Very likely the caribou are subject to a disease similar to necrotic stomatitis common among the elk in the States.

A cow found dead July 15, 1940, had probably succumbed from some kind of internal infection. Pus completely filled one lung and part of the other. On the tissue adjacent to one lung was a nodule of pus 2 inches in diameter.

Concerning disease of caribou, O. J. Murie (1935, p. 9) writes as follows:

No opportunity during this investigation was had to make a careful study of caribou diseases, but none of the observations made indicated that these animals are subject to disease to a serious degree. Seymour Hadwen and L. J. Palmer (1922) discuss various diseases and parasites found among the domestic reindeer, and some of these may occur in caribou. They found, however, that in a number of cases conditions were aggravated by close herding, and it is therefore probable that the caribou—scattered over a wide territory—are much less susceptible to disease than are the reindeer.

The caribou move about so much that losses would not be easy to discover, but so far as we know the losses from disease are not great.

Some Predator-Caribou Relationships

LYNX, WOLVERINE, AND CARIBOU

No signs of lynx were noted; the wolverine was relatively scarce and so secretive that no observations on this animal in relation to the caribou were made. During calving time both of these species might prey on calves, but ordinarily the predation would be unimportant.

COYOTE AND CARIBOU

So few coyotes are present in the park that no data were secured on their relationship to the caribou. If numerous they might kill a few calves, but it seems probable that a cow could generally ward off a coyote attempting to get her offspring. A young bull kept in captivity by my brother and me in 1923 showed much dexterity in the use of its hoofs. When we tried to force him to one side of a corral with a rope he struck the rope on the ground fiercely and accurately with fore hoofs and then with hind hoofs. This bull was full of spirit and often chased us when we came near. Only the heavy toggle to which he was tied stopped his rushes. This exhibition in the use of the hoofs indicates that they could be used effectively on a coyote.

GRIZZLY AND CARIBOU

On May 28, 1941, a lone grizzly and a pair of grizzlies were seen between Teklanika and Savage Rivers where many caribou calves were being born. The lone grizzly was surprised feeding on the carcass of a very young calf, and a little later it was seen feeding on another calf carcass. The pair of grizzlies was also feeding on calf carcasses.

On May 29 a large herd of caribou was noticed moving away from two approaching grizzlies. The bears did not follow the herd, but the general movement of the caribou indicated that they considered the grizzly an enemy.

After the first few days the calves are probably fairly safe from grizzly attack unless taken by surprise. But before the calves gain strength and speed the bears evidently are able to get some of them. The total effect of grizzly predation is not large, however, for there seems to be no special movement of grizzlies to the calving grounds, and the few bears preying on calves would not take a heavy toll. Some of the calves eaten probably represent carrion, and there would be many afterbirths which might also attract bears. No information indicating bear predation on adults was secured. The best time for predation on weak adults would be in the winter, and at this period the bears are not active. Six adult caribou were found eaten by bears. Two of these carcasses were greatly decayed when eaten. Some of the caribou eaten were known to be carrion and the probability is that they were all dead when found by the bears.

GOLDEN EAGLE AND CARIBOU

Eagles are known to prey on caribou calves but the number they kill is insignificant. Not only is the number of eagles extremely small in proportion to the number of calves, but also, so far as I could determine, the eagles seldom prey on young caribou, which are vulnerable to eagle attack for only a short period.

A Mr. Brown, an Alaska Road Commission foreman, told me of an interesting incident which occurred about June 13, 1938. He saw a calf left behind by a startled cow. Soon an eagle appeared and commenced to swoop at the calf, which warded the eagle off by rearing up on its hind legs and striking at it with front hoofs. The calf finally took refuge in some willows. When it came forth, two eagles began swooping at it. Once it struck one of the eagles with its forelegs and caused it to cry out. For a few seconds there was a mingling of calf and eagle. The besieged calf again took refuge in the willows, where it lay down. When it emerged, two more eagles had arrived and four eagles were swooping at it. After fighting them off for a time, it again hid in the willows. The eagles were perched on the ground in the general vicinity of the calf when Mr. Brown left the scene. It was surprising that the calf was able to put up such a spirited defense. If the cow behaved normally, she would in time have returned to her offspring. Lone calves evidently sometimes fall prey to eagles but probably a calf with its mother is seldom attacked.

On June 14, 1939, I found the carcass of a recently killed calf east of Toklat River. While I was examining it, an eagle soared over head. It had been feeding on the dead animal, and wounds indicated that the bird had killed it. The talons had punctured the hide and penetrated the muscle on both sides of the neck. The skull was cracked from one eye to the antler but on the opposite side. At this point there were no punctures in the skin, so it appeared that the skull had been cracked by a blow from the eagle. The wounded areas were all bloodshot. Only the eagle had fed on the carcass.

Later in the day another eagle was seen perched on a dead willow 2 feet from the ground. Twenty-five yards from the perch was a freshly killed calf. Part of the brisket, lungs, and tongue had been eaten and a part of one jaw had been torn loose. There were talon marks surrounded by bloodshot areas on the left shoulder and just behind it. The rear part of the skull was cracked open, apparently by a blow, as the skin was not punctured. The evidence indicated that an eagle had killed this calf, too.

Both calves were probably less than 2 weeks old. They were found where large herds had recently passed, so it is possible that they had strayed and had been left behind. As mentioned elsewhere, calves are occasionally lost, especially when large herds are suddenly disturbed. The above observations are the only ones which showed calves being molested by eagles.

Relation of Reindeer to Caribou

The domestic reindeer is a smaller animal than the fine, large Alaska caribou. Unfortunately the two animals readily cross, so that when reindeer are brought into caribou country there is grave danger of the caribou herds deteriorating because of cross breeding. In view of this danger the reindeer herds should be kept away from the region inhabited by the caribou.

In 1922 a large herd of reindeer was brought through Mount McKinley National Park and for a few years was kept in the Broad Pass region. During the drive many reindeer strayed and joined the caribou. Since the caribou migrated to the Broad Pass region at the time the reindeer were kept there, some reindeer had opportunity to join the caribou herds. The reindeer at Broad Pass were permitted to stray and now are entirely gone. Many crossings no doubt were made with the caribou and, although they may have had some effect on the herd, it is not now noticeable. It is fortunate that the reindeer in that region were exterminated. Perhaps the wolves were an important factor in ridding the caribou country of these reindeer.

Wolf Predation

PREDATION ON ADULT CARIBOU

Despite the fact that there is much wolf predation on adult caribou one must be cautious and examine all accounts of such predation critically. A surprising number of reports, both written and spoken, do not bear scrutiny. One evening in 1939 some boys told us that they had just witnessed two wolves pull down a cow caribou. They gave a vivid account of the incident and told us where the hunt had occurred. After supper three of us set out to examine the carcass. We found it, but the animal had been dead at least a week. The hair slipped all over the back and even on the legs. The boys had probably seen one or two wolves at the carcass and had made a good story of it.

Another similar incident is also interesting. A man had come into Fairbanks from the direction of Circle with a report that wolves were killing great numbers of caribou, and described how a pack of wolves had killed a number of them. The story passed many lips. A man interested in wolves hunted up the observer to get particulars. The observer said he saw tracks of a band of wolves and one caribou they had killed. For the sake of accuracy, he was asked if one wolf could not make many tracks. The observer admitted that one wolf might make as many tracks as he had seen. He was asked how he knew the wolves had killed the caribou and if it wasn't possible that hunters had killed it since it was near the road. The observer did not know about that. In this instance, although the wolves may well have been killing many caribou, the observer had little evidence on which to base his assertions. It illustrates how an erroneous evaluation of a situation from the quantitative standpoint may be built up in the public mind.

Most of the predation on adult caribou seems to occur during the fall and winter months. During the calving period and throughout the summer the calves, when available, are preyed upon and apparently only a few adults are then killed. But sometimes there are stray adults and no calves and then probably adults are hunted. It seems that wolves run the adult caribou until they are exhausted, for in a short chase the grown animals can run away from the wolves. At times perhaps wolves may maneuver so as to bring a caribou down more quickly. Weak and lame animals would not be expected to run very far.

On October 14, 1940, tracks were seen which showed that at least four or five wolves had been chasing a large bull caribou which had galloped in a straight course through a patch of spruce. Along the trail there was some blood which may have come from bruised feet rather than from wounds inflicted by the wolves. The chase emerged from the spruces and went out on the gravel bar where tracking became difficult. But it was obvious that a large caribou had been chased by the wolves. A carcass was found later in the general area, but there was no way of knowing whether or not it was that of the animal that had been chased by wolves.

On March 19, 1941, on the rolling hills between Savage and Sanctuary Rivers I came upon the trails of four galloping caribou. Trails of two wolves showed that they were running after them. The chase had swung over to the north side of a broad basin, through a fringe of spruce, across to the south side, and up a rather steep ridge. Two caribou continued climbing the ridge to the top, but the other two, when near the top, cut down the ridge, galloping through a heavy growth of willows which filled the bottom of the basin. All the way the snow had been about 18 inches deep, but here it was even deeper, and the caribou broke through to their bellies. When the wolves came to the place where the four caribou had split, it may be significant that they gave chase to those which had failed to climb the ridge and had run down hill. After running down hill the two caribou floundered through the deep drifts among the willows in the hollow, then gained a slope on the other side largely free of snow. Here they followed some low ridges where the travel was easy and then started to climb the long slopes of the Outside Range of mountains. It was too late to follow the tracks far up the mountain so I never learned if the wolves overtook the two caribou. I had followed the chase for 3 or 4 miles.

On the morning of July 2,1941, I saw three wolves on the middle of East Fork bar. They were from the East Fork den and consisted of the gray female, the black-mantled male, and the light-faced male. They watched me for a few minutes, then the black-mantled male trotted slowly to the east slope. The light-faced male trotted a few yards to the carcass of a caribou but in a moment followed the other male. The female trotted up the bar toward the den. Four hours later I examined the carcass which proved to be that of a young cow. It was still warm, hence the wolves must have killed it that morning. There were several bloodshot tooth marks on the neck. The animal had not been hamstrung. At this time the caribou herds were far to the west so that the only caribou available were stragglers.

Otto Geist of Fairbanks told me that he once saw a caribou run past him with tongue out, obviously weary. A little later a wolf appeared on the trail and it also seemed weary. The next morning Geist followed the trail down river to the end of the chase. The wolf had killed the caribou, had eaten his fill, and was sleeping on the river bank opposite the carcass.

It is well known that wolves kill adult caribou but it is difficult to learn what proportion of the caribou killed are below standard in strength. It is hard to know how "nip and tuck" the relationships are between the two species; how many healthy caribou chased by wolves escape, and how many succumb.

PREDATION ON CARIBOU CALVES

In the spring the wolves prey extensively on the calves. The first day or two after birth they cannot run fast enough to give the wolves a chase, but in a few days they can almost keep up with the cows and then they force the wolves to do their best. In no instance was the wolf seen stalking caribou. Such maneuvers are unnecessary, for the wolf has no difficulty in approaching within a few hundred yards of them. Generally the caribou seem not to be worried much by wolves unless chased. Bands were frequently noted watching the wolves when they could have been moving away to a more secure position.

The wolf's method of hunting calves seems to give an opportunity for the elimination of the weaker animals. Usually the wolf chases a band of cows containing several calves. The speed of the calves is only slightly less than that of the wolves, at least on level terrain, so they make the wolf do his best, and the chase continues long enough for a test of the calves. The weakest, the one with the least endurance, falters after a time and drops behind the others, and this is the one the wolf captures. In some instances I suppose a calf falls behind because it is younger than the others, but after these animals are a few weeks old the differences in time of birth probably are unimportant, and the one actually weaker than the others is the one that succumbs. Thus the wolf appears to be a factor in maintaining quality in the herds.

There may be more weak animals in populations than has been generally realized. In this connection some observations of the elk in Jackson Hole, Wyo., are pertinent. In the spring of the year there is much variation in the strength of the yearlings. If a large herd is started running, some of the yearlings may be seen to collapse, exhausted by their efforts. Most of these animals at this time are able to rise again after a rest, being weak only from the winter hardships. Others are apparently diseased for they die soon after tumbling. In the presence of a predator probably these weaker animals would be eliminated as the winter progressed.

HUNTING INCIDENTS

For a better understanding of the hunting habits of wolves and the behavior of the hunted caribou, a number of illustrative incidents are here described.

Typical Wolf Hunt.—On June 16, 1939, I had my first full view of a wolf capturing a caribou calf. My assistant, Emmett Edwards, and I were sitting on a ridge high enough above the river bars to give us a good view of the prospect before us. We were classifying according to sex and age the bands of caribou passing up the river. All day, band after band passed us, going up the west fork of the Teklanika River to the glaciers of the high Alaska Range; others were coming down this fork and going up the east fork. About noon we noticed in the distance a band of about 250 caribou, mainly cows and calves, coming downstream. Soon they were near enough so that we could make out that they were galloping. Suspecting that they were being disturbed, I looked through the field glasses and saw a black wolf galloping after them. When the caribou reached the triangular flat between the forks of the river in front of us, the wolf was close upon their heels. The caribou in the rear fanned out so that they were deployed on three sides of the wolf. He continued straight ahead, continuously causing those nearest him to fan out to either side, making an open lane through the herd. Those on the sides stopped and watched the wolf go past. Soon most of the caribou were on either side of the wolf's course.

On the flat the wolf stopped for a moment and so did all the caribou. Then he continued straight ahead after a band of about 30, and these again fanned out, whereupon he swerved to his left after 15 of them, which then started back in the direction from which they had come. The wolf chased these for about 50 yards and stopped. Small bands of caribou, some of them only 100 yards away, almost surrounded him. It seemed strange that they did not run away from the vicinity of danger. Then the wolf seemed to have come to a decision, for he started after 25 cows and calves farther from him than those he had just been chasing. Before they got under way he gained rapidly. For a time the race seemed to be going quite evenly, and I felt sure the band would outdistance their enemy. But this was my first view of such hunting activity and I was mistaken.

The gap commenced to close, at first almost imperceptibly. The wolf was stretched out, long and sinewy, doing his best. Then I noticed a calf dropping behind the fleeing band. It could not keep the pace. The space between the band and the calf increased while that between the calf and the wolf decreased. The calf began to lose ground more rapidly. The wolf seemed to increase his speed a notch and rapidly gained on the calf. When about 10 yards ahead of the wolf the calf began to veer from one side to the other to dodge him. Quickly the wolf closed in and at the moment of contact the calf went down. I could not be sure where the wolf seized it, but it appeared to be about at the shoulder. The chase had covered about 500 yards and the victim was about 50 yards behind the herd when overtaken.

In a few minutes the black wolf trotted a short distance to meet a silvery-maned gray wolf which was limping badly on a front foot. Together they returned to the dead calf, sniffed it, then moved off, and circled to the left side of the ridge at the forks and climbed it slowly. Halfway up the slope they rested for a half hour, and then they continued to the top of a promontory about 1,000 feet above the river bars. On the way they flushed an eagle which circled and twice swooped low over them. The wolves lay down on the point of the ridge until 7 p. m. At this time we decided to examine the calf carcass and descended from our ridge, taking advantage of a high bank along the river to keep out of sight of the wolves.

When we reached a point on the bar opposite the kill we saw the limping gray wolf coming down the slope. Then we saw the black one feeding on its prey about 300 yards up the slope from where the kill had been made. He had no doubt carried the carcass while we were walking along the bar. Several runs were made at six or seven magpies which were feeding with him. Soon the wolf left, returning once to chase the magpies from the meat. The gray animal which had been lying a short distance above the black one then approached the meat and carried off a large piece. When we reached the spot there were only a few ribs and some entrails left. As we walked towards camp the gray female was again seen resting on top of the ridge.

Unsuccessful Hunt.—On June 17 we returned to the forks of the Teklanika to watch the wolves. A band of 15 caribou, without calves, trotted along the bar followed by a trotting gray wolf. When the wolf stopped to sniff at a fox den the caribou stood watching him from a distance of only 75 yards. The caribou moved off and the wolf disappeared, perhaps to rest.

Later in the morning (about 10 o'clock) eight or nine cows and four calves were seen galloping across the river bar followed by a gray wolf loping easily. They all crossed the east fork of the Teklanika River and came out on the flat where the day before a calf had been killed. The wolf galloped rapidly across the flat after the fleeing caribou, which with a long lead reached the rough country at the base of the ridge. The wolf gained on the caribou while they ran up and down the slopes and it ran on the level, but when the wolf also reached the rough country it was quickly left behind. On top of the first slope it gave up the chase after running somewhat over a half mile.

An Afternoon Hunt.—On June 1, 1940, from a lookout near the East Fork den I saw an interesting hunt. At this time there were many bands of cows with calves, some feeding only a quarter of a mile from the den. One group walked within 50 yards of it. From the lookout I counted 1,500 caribou. At 4:40 p. m. the black-mantled male looked into the den and then walked down to the bar. He was followed closely by Grandpa, and shortly the black male came out of the den and also followed. It looked as though the black-mantled male had looked into the den to let the black male know he was going hunting. The three disappeared in a ravine leading up the long slope. Grandpa was limping badly on a hind leg, not using it at all when he galloped. The gray female started late, after the others were in the ravine. The black female was left to watch the den, resting near the entrance.

Far up the ravine the black-mantled male, followed closely by the black male, appeared on a large snowdrift. The black-mantled male waited for the black male and when it came up, jumped and romped with him. The wolves seem to enjoy romping on these late spring snowdrifts, and I have seen mountain sheep also jump about and play on them. The female wolf was following a couple of hundred yards behind. The black-mantled male turned southward at right angles and followed a bench. The others turned also, about 100 yards lower down the slope. Far in the rear appeared Grandpa, still limping badly. He turned about a third of a mile below the others, being out of their sight on the slope below the bench on which they were traveling. They moved southward, the black-mantled male loping in a rocking-horse fashion, apparently from excessive spirits. Several bands of caribou in front of the advancing wolves galloped rapidly up the steep slope. A mile or more to the south I lost sight of all except Grandpa, who had stopped and howled.

Soon the others had swung around Grandpa, who acted as a pivot, and they all moved northward again toward the den. The black-mantled male was just below Grandpa and far down the slope came the black male and the gray female. By the time these three came abreast of Grandpa, about 200 caribou in one band, and some smaller bands, were galloping northward ahead of them. Some of the caribou ran up the slope. The larger band was followed by a grizzly galloping below and parallel with it. The bear seemed to be hurrying to get away from the general commotion. He veered off to the river bar and there stood up on his hind legs and looked up the slope in the direction from which he had come. Then he dropped to all fours and continued across the bar.

The wolves stopped soon after they had started northward, and the black male howled. When the black-mantled male answered him from up the slope, all the wolves assembled on the high point where he stood. They lay down for a few minutes, then the black male moved down the slope at an angle and chased some caribou. For a time the caribou did not run, so the black male was well within 250 yards before they began to flee. He galloped hard up a low ridge and down into a shallow ravine where he captured a calf after following it in a small half circle. In about 10 minutes the black male came out in the open and howled, whereupon the three wolves on the point started toward him. The black male trotted toward the den, turning aside on the way to follow the fresh tracks of a cow and calf for several yards. The black male arrived at the den at 6:20 p. m., 1 hour and 40 minutes after leaving it. He disappeared in the den for a few minutes. Soon the other three wolves returned and the gray female immediately went into the den, while the two gray males walked up above to lie down. The last three wolves arriving had not gone to the kill but had come directly to the den.

The first part of the hunt seemed to follow a system of herding the caribou, but after the wolves assembled on the point three of them took no further part in the hunt.

Three Male Wolves Seek Calves.—Preceding the departure for this hunt there had been much tail wagging and some howling, which has been described in the wolf chapter beginning on p. 32. After the ceremonies, at 7:30 p. m., the three males trotted across the bar westward parallel to the highway. The two females remained behind, lying a few feet apart near the den and watching the departing hunters. The males were out for the regular night hunt. All day caribou had been in the vicinity of the den, but the resting wolves did not molest them.

Soon after their departure, caribou on the flats ran off in various directions, showing that they had seen the hunters. The wolves kept trotting southwestward. The black male, ahead and to the right, soon passed out of my sight behind a ridge. The black-mantled male was far out on the bar, and Grandpa was out of sight near the black male. The wolves crossed the neck of tundra between two forks of the East Fork River. In the meantime I hurriedly returned to the road and drove westward in my car, stopping on Polychrome Pass high above the rolling tundra over which the wolves were traveling.

Small bands of caribou were scattered over the tundra below me. Now the black male was far ahead of his two companions. As usual he seemed to be doing most of the hunting. He approached two or three bands in his course and watched them while they ran away. In these bands there happened to be no calves so I wondered if the wolf was looking over each band to see if calves were present. The two grays caught up with the black male, and part of the time the large black-mantled one was in the lead, trotting gaily and briskly with tail waving. Once he dashed at a band, then stopped to watch. The scattered caribou came together in a bunch and ran off. There were no calves. Once the black male galloped hard after a herd but stopped to watch when he was near to it. As the wolves continued traveling the mantled male lingered far behind and from a knoll in the tundra raised his muzzle and howled. He was answered by the deep, hoarse howl of one of the wolves in the lead. After traveling 5 miles they again were together and as yet had made no serious effort to kill caribou. There were many calves in the country, but the small bands containing 15 or 20 caribou which the wolves had encountered along the way happened not to have any. It appeared that the wolves were searching for calves. At 10 p. m. the wolves crossed the road and went out of sight behind a ridge.

Some of the bands that ran from the wolves went off to one side only a few hundred yards. Others which went straight ahead in the course taken by the wolves ran as much as a mile. Some bands fled because they saw others run, and on a few occasions took a course nearer the wolves.

The Black-Mantled Male Feeds Alone.—On June 4, 1940, at 5:45 p. m., I saw the black-mantled male howling as I was going to the den. He was lying on a knoll a mile from the den. In order not to disturb the wolves I retraced my steps. For 5 minutes after I reached the road the wolf continued howling at short intervals and then he trotted briskly toward Sable Mountain. When I arrived at a point where I could get a view of the slope, I saw about 250 caribou, including calves, running hard. Then I noticed the wolf feeding on something, probably a calf caribou. Whether he had just made a kill or had returned to an old kill I do not know but I suspect that it was an old kill. He fed about 10 minutes, then lay down beside the carcass and stretched out on his side. At intervals of 10 or 15 minutes he raised his head for a look around. While the wolf was lying there, small bands of caribou passed near him. One band of 10 adults and 3 calves passed within 50 yards of him. After these had passed he looked up, then galloped easily after them for a hundred yards, stopped, and after watching them a few moments, slowly returned to his resting spot. The cows and calves fled full speed along the base of the mountain, a calf leading the flight. At 9 o'clock the wolf trotted slowly westward.

The Two Gray Males Chase Caribou.—In the dim twilight of June 13, 1940, south of Polychrome Pass, two wolves which appeared to be the black-mantled male and Grandpa were harrassing some bears which probably had raided their kill. After a half hour the two wolves trotted westward and from above approached a herd of about 200 caribou which included many calves. Both wolves galloped hard toward the caribou, which angled up a slope. After a few hundred yards of running, the rear wolf stopped, and then chased a lone adult caribou which was standing nearby. This caribou was chased for 200 yards and then the wolf started up the long slope toward the herd its companion was chasing. Near the main Alaska Range where the chase led, the shadows were so deep I could not see all that happened. But after the herd had gone almost up to the rugged slopes it had turned westward to a broad flat between two ridges. A little later the wolves were chasing the herd up this relatively level flat to near the head of the valley but then the animals were again lost in the deep shadows and I could not see if a kill was made. A half hour later the two wolves were back harassing the bears. The early return of the wolves suggested that they had not been successful, but in any event the caribou had given the wolves a long chase.

A Cow and Calf Hurry Away From the Wolves.—Usually the caribou did not run far from a wolf unless pursued, but on June 16, 1940, a cow and calf were seen galloping across the east side of Sable Pass. Evidently they had winded four wolves which were approaching. The caribou traveled a mile and a half or more while we watched and, still hurrying, disappeared behind some hills. Later the four wolves appeared but were not on the trail of the cow and calf.

To hunt, the wolves had gone to Teklanika Forks, 10 miles or more from the den, and yet during the day at least 400 caribou had been feeding a mile or two west of the wolves, and at least two bands with calves had passed within a quarter of a mile of them. Wolves seem to enjoy traveling and probably have favorite hunting grounds.

Black Female Goes on a Short Lone Hunt.—On June 17, 1940, only the two females were seen at the den. Grandpa was seen at Teklanika Forks 10 miles away and perhaps the other two males were also spending the day there. The black female seemed restless all day; perhaps she was hungry. At 5:30 p. m., as it commenced to rain, she trotted to the den, then over to the gray female lying 50 yards away, and, after stopping with her a moment, trotted across the river bar. In about 5 minutes she appeared south of me, about a mile from the den, chasing a large band of caribou containing many calves. Some of the caribou ran off to one side and soon began to feed. A calf brought up the rear of a group she was chasing. When it appeared that the wolf might overtake the calf, most of the band and the rear calf veered upward to the left and seemed to increase their speed. The wolf singled out another calf which was running straight ahead with four or five adults, but in a moment the chase went over the ridge. Then it commenced to rain so hard that the visibility became too low to see anything. It seemed to me that the wolf might be successful.

Caribou Escape After Short Run.—On June 19, 1940, the five adult wolves were observed near the den from 8:30 a. m. until 6:10 p. m. A half mile north of the den at 11 a. m. one of the black wolves chased a band of 35 cows and calves for about 400 yards and then gave up without catching any calves. During the day five bands of cows with calves, averaging about 100 animals in a band, passed within a third of a mile of the den without being molested.

A Maneuver by Two Wolves.—On June 22, 1940, at 8:35 p. m., the black-mantled male and the black male followed the river bar southward from the den. About 3 miles away 200 or 300 caribou were feeding on a grass-covered flat. For about a mile the two wolves trotted together; then the gray one fell far behind. He moved along the east bank while the black one trotted briskly diagonally across the river bar toward the caribou. When about 200 yards from them he watched for about a minute as though to size up the situation, then started galloping forward. He ran in such a way as to drive all the caribou off the grass-covered flat toward the gravel bar. He did not try to catch any of them but was definitely herding the scattered animals. When he had run the length of the scattered herd and had the caribou all galloping out on the bar he swung around the front end of the herd and then came back chasing them all before him. As the wolf caught up with a band it would veer off to one side. Then he continued straight ahead to the next little band which in turn would veer off to one side. Finally he stopped, sauntered over to the bank, wandered around as though investigating the area, then trotted across the bar in the general direction of the den. He went into some willows where he probably lay down for I saw him no more. The caribou moved on westward along their migration route, feeding as they went, behaving as though they had completely forgotten the chase.

The black-mantled male wolf in this hunt lingered on the other side of the bar. Some of the caribou which had been driven out on the bar had drifted over near him and he had chased a band up in the tundra. They ran far to the east, but the shadows were so deep that I could not follow the hunt closely enough to learn whether any calves were killed. I was able to see the running caribou, but caught only an occasional fleeting glimpse of the wolf.

I do not know whether the hunt had followed a general pattern of cooperative maneuvering but it might be so interpreted. In this case there was no great advantage gained by the wolves but under different conditions the maneuvers could be advantageous to them. If the black wolf had chased the caribou toward the gray wolf far enough to tire the caribou somewhat then the gray wolf could have taken up the chase fresh.

A Long Chose.—On June 23, 1940, at 9:30 a. m. I saw 250 or more cows and calves running hard, a mile or more east of Toklat River. A wolf, apparently the black male of the band, was chasing them. The wolf chased one group after another, so that he finally had the various groups running in different directions. Although galloping hard he did not bear down on any herd. It looked as though he were testing the groups, looking for a specially vulnerable calf. After considerable chasing, the wolf ran after four adults and one calf, driving them off by themselves. The calf broke off to one side and kept veering as though trying to return to the herd, and in so doing lost ground, for the wolf could then cut corners. When the wolf was apparently about 20 yards behind the calf, it was unable to reduce the gap for some time, but when the calf began to zigzag it lost ground. The wolf gradually reduced the distance to a few yards, but still the chase continued for another 200 yards or so. For a time I thought the calf might escape, so well was it holding up. But the wolf finally closed in, and the calf went down. While the wolf stood over the calf, apparently biting it, it jumped up suddenly and ran for 75 yards before it was again overtaken. A few minutes after disposing of the calf the wolf trotted a short distance toward the herd, then returned to his prey. The caribou herd continued on its way westward.

Caribou Undisturbed By Wolf Howling.—On June 25, 1940, at about 5 p. m., more than 200 cows and calves came out on the bars above the East Fork wolf den. They were strung out in a long straggly line, feeding as they moved. A wolf howled from a short distance above the caribou and soon its howls were answered by two or three wolves at the den. Although the caribou were between the lone wolf and those at the den, they continued feeding. I could not see that any of them heeded the howling. About this time a heavy rain obliterated the view, and it continued raining all evening so no further observations could be made.

Three Calves Killed By Wolves.—When the calves are only a few days old the wolves can kill them with little effort. On May 29, 1941, two calves, probably 2 or 3 days old, were found dead, 25 yards apart, between Sanctuary and Savage Rivers, where hundreds of calves were being born. Birds had fed a little on each. Bloodshot wounds on neck and back were such as to make it plain that the calves had been killed by wolves. Some neck vertebrae of one were crushed. Very likely the two calves had been killed about the same time. Less than a half mile from these two carcasses I saw a lone cow smelling of a calf. She walked away a few steps and then returned to smell again. Then she moved off 200 yards to feed. I walked to the calf and found that it was dead. On skinning it, I found tooth marks around the head and back, which apparently had been made by a wolf. The calf was only a day or two old. The three calves had been killed within the preceding 24 hours.

The Black Male Easily Captures a Calf.—On June 29, 1941, at about 3 p. m., my attention was attracted by a band of about 400 caribou running over the rolling tundra a mile west of the wolf den. The black male wolf first ran toward one end of the band so as to chase the caribou forward. The herd broke up into groups of 50 or 60, and the wolf dashed along in the middle, and I could not be sure of the status of the chase. Then the wolf started after 50 cows and calves. There was a chase of about a half mile, and the wolf kept closing in upon the herd. Once he stumbled as he galloped, and rolled completely over. But he was quickly on his feet, and little time was lost. Then a calf dropped behind the others. This seemed to encourage the wolf to put on added speed, and in less than a quarter of a mile he overtook the calf, knocking it over as he closed in. The wolf was hungry and fed for about half an hour. This calf was captured more readily than usual.

Crippled Wolf Hunting Caribou Calves.—Foreman Brown of the Alaska Road Commission camp told me that on June 29, 1941, at Stony Creek, he had seen a gray wolf with a crippled hind leg chasing calves with no success. After chasing some bands without catching any calves the wolf moved off and waited for the herds to approach. But while the caribou were still some distance away it jumped up and gave chase. It had good speed for a short distance but quickly tired and fell behind. It caught no calves while Mr. Brown was watching.

A Lone Calf Captured.—About 10 a. m., July 19, I saw the black female wolf on the East Fork bar circling back and forth with her nose to the gravel. She made a sweep of 100 yards downstream, then returned up stream, and finally waded the river. After crossing the stream her ears were cocked forward and she started on an easy lope up the creek, apparently focused on a definite point. I looked ahead of her and saw a caribou calf lying on the bar beside the creek, watching the wolf. When the wolf was about 150 yards away the calf jumped up and galloped upstream. It crossed and recrossed the creek a dozen times, and every time the wolf followed. The calf did not seem to be as speedy as much younger ones had been, for the wolf was running rather easily and gaining. A full half mile from the start the calf, now hard pressed, wallowed in a deep part of the stream and on the next leap stumbled and fell. In a jump or two the wolf caught up and pulled the struggling calf, which once gained its feet for a moment, across the deep part of the stream to the shore where it was quickly killed. The main herds had passed westward some time before, so this calf was a straggler and may therefore have been a weakling. Upon examining the gravel where the wolf had been sniffing around in circles, I found fresh calf tracks. I believe the wolf had not seen the calf before I arrived because a short while before she had been observed 3 miles up the road.

Animals Found Dead From Causes Other Than Predation

One encounters enough carcasses on the range to indicate that quite a number of caribou die from natural causes other than wolf predation. Sometimes upon examining these carcasses no cause for death can be found; at other times diseased conditions are evident. Below is information regarding some of the carcasses found on the range which were sufficiently fresh that I could at least eliminate predation as a cause of death, and in some cases determine the cause.

May 1939.—Ranger Edward Ogston reported that some caribou calves lost their lives in crossing McKinley Fork. During May 1939, the stream was open in places but was bordered by perpendicular walls of overflow ice several feet in thickness. He saw calves go into the streams and fail to get out. Since hundreds of cows with calves crossed the stream at that time, he thought that several of the calves probably were trapped by the overflow ice. The number of calves lost in this way is probably small.

July 21, 1939.—The carcass of a cow which was found on a tributary of East Fork was being eaten by eagles and magpies. There was not a bear or wolf track leading to it so it probably was not a victim of predation. No cause for death could be determined.

August 8, 1939.—A cow which had recently died had severe necrosis around the lower molars. It appeared that the necrosis was sufficiently severe to have weakened the cow and possibly killed her.

May 19, 1940.—A newborn calf was found dead. Apparently it had died at birth. No doubt a certain percentage of the calves die at birth. No food was found in the alimentary canal.

June 2, 1940.—Near Teklanika River a yearling was examined which had been reported hamstrung by wolves. The hide had been bruised on one tendon but the tendon was intact. The joint below the tendon was swollen to about twice its normal size and was bursting with pus. There were no tooth marks on the joint. Apparently the infection had killed the yearling.

June 7, 1940.—The carcass of an old cow was found which had not been fed upon. There was no indication of what might have caused her death except that she was very old.

July 15, 1940.—Late one evening a Road Commission employee arrived with a message from photographer Al Millotte stating that there was a dead caribou in a tributary of Igloo Creek. I drove there that night to examine the carcass while it was still intact. The caribou had died within the last day or so. Two legs had been carried away and birds had eaten the meat from the backbone. The animal was an adult cow. Upon examining the organs I found one lung completely filled with pus, the other partially filled. The tissue adjacent to the lung was in one spot swollen with pus, forming a round ball 2 inches in diameter. This infection was, no doubt, the primary cause of the animal's death. I dragged the carcass out of the water and in a few days wolves and bears had consumed the flesh and dragged away the bones. The main caribou herds had moved westward so this one was a straggler which had been left behind.

June 2, 1941.—On the flat on top of Sanctuary Mountain I found a cow with one antler shed. The animal had been dead for about 2 weeks. There was an unborn calf, normal in appearance and as large as one already born. The only indication of disease was blood in the nostrils. The animal had not been killed by wolves. Later it was eaten by bears.

Crippled Caribou

Figure 50: A caribou calf bruised beyond recovery by a fall in the rocks. [McKinley River, June 25, 1939.]

Crippled animals were noted on several occasions. Often they brought up the rear of a band. Most of the crippling was probably due to natural accidents since the herd is not hunted heavily by man. These crippled animals would be highly vulnerable, and probably are the first to succumb to the wolf. Those seen are listed to give an indication of their prevalence. Perhaps if the wolf were absent more cripples would have been evident. One trapper told me that since the wolves became common he has seen far fewer crippled caribou.

June 10, 1939.—The front leg of a cow was bent as though it had been broken and had later healed. She had a decided limp.

June 14, 1939.—A cow was noted limping on a front foot.

June 16, 1939.—Two cows limped decidedly. Both were lame on a front foot.

June 19, 1939.—A cow, limping badly on a foreleg, brought up the rear of a band.

June 25, 1939.—Near the base of some steep cliffs and talus slopes I found a calf which was breathing with difficulty, unable to stand. Upon examining it, I found a femur and mandible broken, and ribs and shoulder bruised. It apparently had fallen in the rocks. There was no cow in the vicinity.

July 7, 1939.—I saw a calf with a severe limp on a front foot. I also saw a very thin yearling with one horn about 6 inches long and the other horn 2 inches long, a stunted condition which indicated that the animal was not normal.

July 9, 1939.—I found an old ulna and radius of an adult caribou which had been broken and later healed. The healing had been accompanied by considerable exostosis. This animal no doubt had been handicapped in traveling.

July 13, 1939.—Bringing up the rear of a band of about 800 caribou I saw a calf limping on a front foot, a thin cow limping on a front foot so that her head went up and down violently with each step, and another cow with a hind leg which most of the time was not used.

July 16, 1939.—A calf, bringing up the rear of a band of about 200, limped badly on a foreleg, hardly using it. In another band there was a cow with a pronounced limp.

July 27, 1939.—Near Teklanika River I saw a lone caribou with a definite limp in a foreleg.

June 7, 1940.—In the rear of a band I saw a cow not using one of its hind legs.

January 8, 1941.—In a band of six, a cow brought up the rear, limping badly.

July 8, 1941.—A lone bull on Igloo Creek was lame.

Calf Crop

At times it is difficult to get a good calf count. Large herds often travel so compactly that many of the calves remain hidden behind the cows. When the herd is lying down the calves are hard to see. Therefore satisfactory counts of resting herds were usually not obtained. In 1939, when I had an assistant, I used field glasses and called off the classification of each animal as it passed and my assistant kept the tally. In this way we classified a number of herds. But in 1940 and 1941 I was alone practically all the time and usually found it extremely difficult to classify the animals accurately. In 1941 when the herds moved westward after the calving period the animals were so massed that there was little opportunity to count calves. During the latter year one herd numbered roughly 4,000 adults, another 1,000, and another 2,000, and the animals traveled in compact groups.

1939 CALF CROP

The counts obtained in 1939 give a fairly accurate figure for the calf crop. On several occasions conditions were ideal for classifying the herds. On June 16, 17, and 18, from a ridge, we observed the caribou moving along slowly on the river bars, often in single file. All of the caribou passing were not counted because of the interruptions caused by other events such as a wolf chasing a caribou calf. In addition, many bands bunched to an extent that the individuals could not be counted. On July 13 another excellent count was secured of a single herd of 827 animals. I was able to classify this herd twice.

To show how the bands vary in calf percentages I have tabulated the classified bands for 1939. See Table 15 (p. 178).

Although the calf percentage in many herds does not vary far from the average, some herds do show extremes. The herd classified on May 24 had practically no calves, while one seen on June 12 had 75 cows and 62 calves, and another herd seen on July 7 had 46 cows and 43 calves. It is obvious that erroneous conclusions on the calf crop could be obtained by classifying only a few bands.

Of 2,493 cows in the herds classified, 1,231, or 49 percent of them were followed by a calf. Since, as stated, some young bulls and yearlings are included in the figure for cows, the calf crop can be considered as being fully 50 percent.

TABLE 15.—Classified. Caribou Counts, 1939

¹Includes unclassified yearlings and young bulls in some instances. The counts of cows were therefore somewhat larger than was representative.

²Bulls were not sufficiently represented in the counts because the main herds of males were missed.

³Young bulls often could not be identified from cows in the moving massed herds.

⁴Indicates that yearlings could not he distinguished from cows. In these cases yearlings were recorded in the column headed "Cows."

⁵Several bands.

1940 CALF CROP

The figures for the 1940 season are not extensive but they signify that the calf crop was about the same as that of 1939. Of the 735 cows classified, 379 were followed by calves, so that the calf-cow ratio was 51:100. Many counts of herds were in agreement with the figures listed in the table below.

TABLE 16.—Classified. Caribou Counts, 1940

¹Includes unclassified yearlings and young bulls in some instances. The counts of cows were therefore somewhat larger than was representative.

²Bulls were not sufficiently represented in the counts because the main herds of males were missed.

³Indicates that yearlings could not be distinguished from cows. In these cases the yearlings were recorded to the column headed "Cows."

1941 CALF CROP

In 1941 I obtained but few figures on the calf crop. Many counts were attempted but were not accurate enough to tabulate. On June 28 two herds were classified. One consisted of 258 cows and 127 calves, the other of 29 cows and 17 calves. The calf percentage in these two herds was 50. From several partial counts my impression was that the calf crop was about the same as in the 2 preceding years.

It is interesting to compare the calf-cow ratio with that of elk, another herd animal. In Teton National Forest, Wyo., in the summer of 1935 O. J. Murie found that 38 percent of the cows were followed by calves and in Yellowstone National Park in 1937 I found 41 percent of the cows followed by calves. Darling (1937) states that the fertility of the hinds of the red deer in Scotland is about 60 percent and says it is the same as given by Cameron (1923) for red deer in the island forest of Jura. It would seem, from these figures, that the calf crop found in the caribou herds was about as expected.

Survival of Calves to Yearling Stage

It is difficult to learn what proportion of the calves survive to the yearling stage because not all yearlings are found with the cows. Many of them join the old bulls or the young bulls and cows. To get an accurate figure one would need a sample of a cross section of the herd and that is difficult to obtain, because many herds consist mainly of bulls and others of cows.

However, from the figures available we can perhaps get a fairly accurate idea of the percentage of yearlings. It will be noted that in 1939, in several bands, the yearlings were not classified separately from the cows. The counts for these bands have been eliminated in determining the ratio of yearlings to cows. In the bands in which yearlings were classified there were 1,727 cows and 385 yearlings. The ratio of yearlings to cows is 22 percent. Assuming that the count is a representative sample, and that the calf crop in 1938 was about the same as in the following 3 years, then it appears that a little more than half, or about 56 percent, of the calves succumbed during the first year. That, it would seem, is a satisfactory survival, although as yet we do not know how large a survival is needed to perpetuate the herd in the case of the caribou.

The figures for 1940, together with general observations, show about the same yearling ratio as was found in 1939, although the figures are meager. Ten small bands of cows were classified on May 12 with the following result: 160 cows and 34 yearlings, or a ratio of about 21 per cent. That represents a survival of about 42 percent of the calves during the year. In June and July, bands were classified which contained 213 cows and 51 yearlings, which indicates a 48 percent survival of calves to yearling age.

In 1941 the survival of yearlings seemed less than during 1939 and 1940, but not enough figures are available to substantiate this impression. Certainly among the caribou wintering around Savage River there were few yearlings. Among three or four hundred cows there were only about 20 yearlings, or a yearling ratio of only 5 or 6 percent. However, the yearling ratio for the herd was considerably higher than this figure for in bands seen later yearlings were more abundant.

There is still much to learn about the mortality of young and the numbers necessary to perpetuate a herd. Different herds, due to many variables, may require different degrees of survival among the young. In areas where there is heavy hunting by man there must be a higher survival of young to take the place of the adults shot. Under natural conditions, perhaps a much smaller survival is needed and desired. A too-high survival of young would increase the herds too rapidly, so that ranges would quickly be overgrazed. At the George Reserve near Pinckney, Mich., where some white-tailed deer were introduced in a fenced area, the survival of fawns for at least 7 or 8 years seemed to be complete. In the wild the survival of young is usually quite different. Under natural conditions a mortality of half of the young seems to be usual. However, we need more data to understand thoroughly the mechanics of wildlife population.

The number of yearling caribou, especially in 1939 and 1940 seemed adequate for the welfare of the herd when compared to the survival of yearlings in other large game animal populations.

Effect of the Wolf on the Caribou Population

It is difficult to determine the effect of the wolf on the caribou. Because the species has maintained itself through the centuries in the presence of the wolf we can expect it to continue to do so under wilderness conditions. The extensive predation on the caribou, especially on the calves, is apparently an important check on their numbers. It is not unlikely that at the present low human population level the wolves serve as a useful cheek on the caribou. If this check were entirely removed the caribou might increase in numbers to such an extent that vast areas of choice lichen range would be severely damaged. Those familiar with the overuse of many big game ranges in the States can readily appreciate the importance of this consideration.

In localities where hunting by man becomes extensive enough to be an important check on the caribou, as it may be in some parts of Alaska, some adjustment in wolf numbers may then be necessary to offset the reduction caused by man. Present information on these details is meager so that it is difficult to decide on management practices. But if man's hunting under the present wilderness conditions that exist over large parts of Alaska is insufficient to keep the caribou in check, then the value of the wolf in this respect should not be overlooked.

The effects of the wolf on the character of the caribou over a long period are also hard to evaluate. The wolves may be an important evolutionary force in changing or maintaining the caribou characteristics.

The Mount McKinley National Park herds appear to have held their own during the last 20 years. Although there has been heavy wolf predation in recent years, the caribou seem to be adjusted to withstand the losses. To care properly for the caribou herds and insure their perpetuation, regular observations should be continued so that their status, together with that of the range, may be known at all times.