Part 1

MAMMALS OF MOUNT McKINLEY NATIONAL PARK ALASKA

by Adolph Murie

Sketches by Olaus Murie

Photographs by Charles J. Ott

Published by the Mount McKinley Natural History Association

Published in cooperation with the National Park Service

Copyright August, 1962 by Mount McKinley Natural History Association

Printed in U.S.A. Pisani Printing Company, San Francisco

CONTENTS

Denali Wilderness 1 Introduction 3 Grizzly Bear 7 Black Bear 11 Caribou 11 Moose 15 Dall Sheep 17 Mountain goat 20 Wolf 21 Coyote 22 Red fox 24 Lynx 26 Wolverine 27 Marten 29 Mink 30 River Otter 31 Short-tailed weasel 31 Least weasel 33 Snowshoe rabbit 33 Collared Pika 35 Hoary marmot 37 Arctic ground squirrel 39 Red squirrel 40 Northern flying squirrel 43 Porcupine 43 Beaver 47 Muskrat 49 Shrews 50 Bat 52 The Mouse World 52-54 Hay mouse Brown lemming Bog lemming Chestnut-cheeked vole Tundra vole Meadow vole Red-backed mouse Checklist of Mammals of Mount McKinley National Park 56

Denali Wilderness

The national park idea represents a far-reaching cultural achievement, for here we raise our thoughts above the average, and enter a sphere in which the intangible values of the human heart and spirit take precedence. Mingled with the landscape of McKinley Park is the spirit of the primeval. The region is dedicated to the preservation of wilderness. Here we try to refrain from the coarser uses of nature legitimate elsewhere.

All the plants and animals enjoy a natural and normal life without human restrictions. Freedom prevails—the foxes are free to dig burrows where they will; to hunt ptarmigan, ground squirrels and mice as the spirit moves; and they share in the ownership of the blueberry and crowberry patches. The grizzlies wander over their ancestral home unmolested; dig roots and ground squirrels, graze grass, and harvest berries according to whatever menu appeals to them. The “bad” wolf seeks an honest living as of yore; he is a respected citizen, morally on a par with everyone else. His hunting of mice, ground squirrels, caribou and Dall sheep is his way of life and he has the freedom to follow it. No species of plant is favored above the rest, and they grow together, quietly competing, or living in adjusted composure. Our task is to perpetuate this freedom and purity of nature, this ebb and flow of life—first, by insuring ample park boundaries so that the region is large enough to maintain the natural relationships, and secondly, to hold man’s intrusions to the minimum.

Most of us feel with Thoreau that “The wilderness is near as well as dear to every man.” We come to McKinley to watch; to catch a glimpse of the primeval. We come close to the tundra flowers, the lichens, and the animal life. Each of us will take some inspiration home; a touch of the tundra will enter our lives—and, deep inside, make of us all poets and kindred spirits.

Our national parks, here in the north, are set aside, not only for Alaskans, or for Americans, but for all humanity. To preserve the delicate charm and the wildness of the region our thoughts must be guided by a morality encompassing the spiritual welfare of the universe.

Introduction

The Mount McKinley region was set aside as a National Park in 1917. The foresighted conservationists who advocated National Park status for this country were activated chiefly by their desire to preserve the flora and fauna in its pristine condition. An effort was made to give the park ample boundaries, but desirable extensions were later made, and it is possible that in the future additional adjustments will be desirable from the standpoint of assuring a self-sustaining ecological unit.

A drive from the Nenana River, the eastern boundary, to Wonder Lake, some 90 miles to the west and directly north of Mount McKinley, is always a fresh adventure. No two days are the same. One day we may see more grizzlies than usual; on another trip we may be especially fortunate and catch sight of a wolf or a wolverine. It is desirable to drive slowly and to stop occasionally to examine the landscape for animal life—the mountains for Dall sheep, the river bars and passes for grizzlies and caribou, and the water, for birds, beaver, or moose.

Some of the birds to be seen along the way are the ptarmigan—willow ptarmigan in the low country, rock ptarmigan on the high passes (the white-tailed are confined to higher elevations and probably will not be seen)—the long-tailed jaegers, the whimbrel (Hudsonian curlew), golden plovers, short-billed gulls, golden eagles, and several kinds of ducks. Ornithologists will be especially interested in seeing such asiatic birds as the wheatear and the willow warbler.

Much of the park is treeless tundra, but strips of woods follow the rivers far into the park, and patches grow here and there on the adjacent mountain slopes. Timberline varies according to soil and exposure; in places it reaches elevations of over 3,500 feet.

White spruce is the common conifer. Black spruce is confined to poorly drained and boggy areas. Along the north boundary I have seen a few patches of tamarack. Cottonwood and aspen are widely distributed and a few tree birches grow at lower elevations. Along the McKinley River an extensive strip of cottonwoods may be seen from the highway.

The tundra supports a growth of willow and dwarf birch. Over twenty kinds of willow occur in the park. They range in size from small forms only 2 or 3 inches in height, to brushy growths 20 feet tall. In places the small willows may grow dense enough to form a sod. These shrubs are highly important for wildlife. Alder brush is widely distributed and plentiful on canyon slopes; near Wonder Lake there are many clumps of alder in the rolling tundra.

The low ground cover over the park consists of mosses, lichens, sedges, grasses, horsetails, and herbaceous plants—many species of each. Early flowers may begin blooming in late April and early May, and at the higher elevations some blooms may be seen in late summer.

The annual berry crop is bounteous and is an important source of food for a host of birds and mammals. Even the mountain sheep have been found enjoying the blueberries. Blueberry, crowberry, cranberry, buffaloberry, and alpine bearberry are all widely distributed. The berries begin to ripen in late July.

With the melting of the snow in the spring, the white landscape of winter is transformed into a brown countryside—brown grasses, sedges, and leafless shrubbery. Snow fields still persist on the mountain slopes, and the spruces are dark green, but brown hues seem to dominate one’s impression of the tundra at this time. In June—the time varies a little with the year—the landscape is magically transformed from a dull brown to the brightest green. Early in August spots of red and yellow colors begin to show. By late August and early September the country is again transformed and we have a world of crimson and other shades of red, trimmed with yellow and gold of willow, aspen, and cottonwood. The alders add contrast for they remain summer-green throughout the autumn color season.

Over much of the country the ground remains frozen below a depth of a few feet. In some shaded areas where the ground is deeply carpeted with moss the soil remains frozen within less than 2 feet of the surface. The continuous thawing of the soil in summer keeps the surface moist until autumn. The thawed surface soil tends in places to creep imperceptibly down slopes as it becomes water-soaked, even though plant life has a strong stabilizing influence. Occasionally the soil becomes saturated with moisture to considerable depths and we have rather large land slides such as the one that recently formed Slide Lake on Stony Creek; the one that shows prominently on the south slope of Sable Mountain; and one to the south of the road at about 3-Mile that caused spruces to lean in various directions. Thawed, water-logged surface soil rests uneasily on the frozen sub-stratum.

A number of parallel, northward-flowing streams head in glaciers lying along the north slope of the Alaska Range. The streams are not large—most of them can be waded without getting too wet—so it is surprising to find them bordered by wide gravel bars. This is due to lack of stream stabilization. In summer the streams carry a load of silt which may be dropped along the way. Channels are continually being gouged out here and filled in somewhere else so that the stream keeps breaking over its sides and forming additional channels. High water, due to a warm day and much glacier melting, or to heavy rains, may cause the streams to flow into entirely new channels. When the main stream reaches the side of the gravel bar it will erode the bank and thus broaden the river bar. This type of erosion is noticeable just below the Teklanika bridge. Gravel bars that have not been invaded for a long period may become covered with vegetation, and it is on some of these old bars that we often see grizzlies digging roots in the spring of the year. But even these bars are temporary. One such bar on the Toklat River was invaded by part of the river a few years ago and much of the sod is being washed away today. Physiographic processes are all very active in the region. On many slopes we see the turf breaking away, and here and there a small land slip.

Those who come to the park the early part of the summer may see extensive fields of ice on the river bars. These are the result of what is called overflow. During cold weather the ice on the streams freezes so thick that there is not room for all of the water to pass under the ice, and since it must run somewhere it develops pressure and breaks out on the surface where it spreads widely underneath the snow. Here it freezes. This process continues throughout the winter and often forms ice patches many feet thick. When one is dog-mushing on rivers the overflow water under the snow is a hazard before it freezes, and the driver of a dogteam must watch to avoid such spots. Conditions are worst during the coldest weather, at a time when a wetting is most serious.

Out in the park there are no trails except for one down Savage Canyon. The country is so open that trails are not needed. The river bars furnish excellent hiking, and even walking across the upland tundra is easy. A number of campgrounds are located along the road between the Nenana River and Wonder Lake.

This booklet is made available as a quick reference pertaining to the mammals in the park. The comments on each species are brief but perhaps sufficient to suggest their status. Distances are deceiving so field glasses should be used in searching the landscape for the larger animals such as sheep, caribou, and bears.

Grizzly Bear _Ursus horribilis_

The grizzly’s domain in the park extends from the glaciers at the heads of the rivers, northward to the north boundary. The grizzly may be discovered on an old river bar, on one of the low passes between the rivers, or traveling high on a mountain slope. One of the favorite haunts along the road is Sable Pass, where each summer one to four females with cubs, along with a few lone or mated bears, take residence.

Any bear seen out in the park is almost certain to be a grizzly because the black bear is confined to the wooded low country along the east and north boundaries. The hump on the shoulder and the dishfaced profile (rather than almost straight, as in the black bear) are good field characters. The general coloration varies from cream color (rare) to straw color, brown, chocolate, and black. The legs are always blackish. The fur fades considerably during the spring and summer. Hence, the new coat, fully developed by autumn, is always darker, and gives the bear a new, fresh look. One old male grizzly, not very fat, weighed 650 pounds. The females are considerably smaller. Because of the long claws on the forepaws, the track of the grizzly can be readily distinguished from that of the black bear, whose forepaw claws are shorter and more curved.

In the spring when grizzlies first come forth from their dens they seem to do much wandering over the higher slopes. At this season I have noted their tracks leading to the remains of sheep, caribou, and moose that had succumbed during the winter. Usually the wolves, foxes, and wolverines have long since feasted on the fleshy parts, but the bears are happy to crush the bones that remain on the premises and thus obtain a taste of the succulent marrow.

The spring and early-summer food is chiefly the root of the peavine (_Hedysarum alpinum americanum_) that flourishes on old vegetated river bars and on many mountain slopes. Using both paws, with their long claws, and straining backward with his body weight, chunks of sod are turned over to expose the thick peavine roots. With delicate strokes, his paws further expose the roots, which taste much like the garden variety of pea. So extensive is the root-digging at times that an area may look like a plowed field when the bear has finished. At this season, because of these food habits, bears can often be seen on the open river bars and on the ridge slopes. Cranberries and crowberries that have wintered under the snow are often eaten in spring.

In June, green vegetation becomes available and a drastic change of diet results. The root digging is terminated for something better. A grass, (_Arctagrostis latifolia_), with a stiff and juicy stalk, and growing in swales and wettish areas, is a favorite. The bears also graze extensively on horsetail (_Equisetum arvense_), mountain-sorrel (_Oxyria digyna_), and the tall showy white saxifrage (_Boykinia richardsonii_). A pea (_Oxytropis viscida_), growing abundantly far up the streams on old river bars is extensively grazed.

The grizzly is quite fastidious in his feeding on dock (_Rumex fenestratus_). He severs the thick juicy stem with a bite and as he chews, the large reddish seed head drops from his lips, neatly discarded.

The grizzlies continue grazing and chomping green grasses and herbs until berry time when another major change of food habits takes place. Some grazing still persists but now the bears turn wholeheartedly to blueberries, crowberries, and the bitter scarlet buffaloberries, the three species of berries most abundant and available. The lush berry of alpine bearberry (_Arctous alpinus_), that ground-hugging woody plant that colors patches of the landscape a brilliant scarlet in autumn, are sometimes eaten, but not with any efficiency. The berry diet continues through the autumn but at this season a few roots may again be sought.

The bear belongs to the order _Carnivora_ and yet little mention has been made of meat in the diet. He is perhaps, so to speak, a victim of evolution and has had to adjust. As his mature size became ever larger through eons of time, he became too slow to catch large herbivores such as the caribou, and his large body required more sustenance than could be secured by digging for mice and ground squirrels under usual circumstances. Therefore he had to turn more and more to vegetation which could be secured in quantity. This is not as drastic a change as we might offhand suppose. It is one chiefly of degree, because we find carnivores such as the fox and the marten turning to a berry diet for a period, from choice.

But it appears that the grizzly would like more meat than is generally available. This I infer from the quantity he eats when he finds a carcass and from the avidity with which bears of all kinds seek spawning fish when available. The only animal that the grizzly consistently hunts in the park is the ground squirrel, but a squirrel contributes only a mouthful and its capture usually requires excessive time and energy. Sometimes a squirrel is surprised and captured before it can disappear in a burrow. But generally a squirrel is secured only after extensive excavating which may involve as much as half an hour, and not infrequently the bear, after much digging, fails to unearth his intended victim. In years when meadow mice and lemmings are especially abundant, bears may make their capture a project which contributes at least a tasty diversion. Caribou and moose calves may occasionally be captured when very young, but the season for this food is short. Occasionally tidings come to a bear’s keen nose that carrion lies upwind, and the lucky bear keeps gorging until only a few bones and patches of hide remain.

After feeding on a carcass the bear often covers it with sod and vegetation. One fall at Stony Creek I watched a bear at a cache which showed up as a dark mound surrounded by a dark circular area from which the sod had been torn loose. For an hour the bear kept methodically raking the surrounding area beyond.

He was scraping the loose vegetation toward the cache, working leisurely with one paw at a time. The loosened material was pushed toward the cache as the work progressed. When I examined the area later, I noted a circular patch, extending out 20 feet from all sides of the carcass, that had been combed clean of loose vegetation. The bear finally lay down on the cache to wait for digestion to create more space for this rich fare.

North of Wonder Lake a grizzly had similarly covered a caribou that a hunter had left lying in the field. The bear was not at the cache, but since most of the carcass was still intact, he probably was not far away. I found some carcasses that were not covered with sod. A mother and two yearlings at Polychrome Pass left a caribou carcass without covering it and retired to some steep cliffs overlooking the area. The following day they rested near the carcass, but still no effort was made to cover it.

Mating takes place in May, June and early July, and a pair remains together for two or three weeks. I suspect that a male might look for a second marriage following the termination of the first. One large crippled male was successfully consorting with two females at the same time, neither female objecting to the presence of the other—in fact, both probably preferred it that way.

The cubs are born in the hibernating den in midwinter, are 8 or 9 inches long, and weigh less than 2 pounds at birth. The number of cubs in a litter ordinarily varies from one to three, two being the most frequent.

The cubs not only nurse throughout the first summer but to about the same extent during their second summer abroad, when they are robust yearlings. I had been surprised to find yearlings regularly nursing, but it was a greater surprise to observe mother grizzlies nursing cubs over 2 years old, in their third summer abroad. The protracted nursing period indicates a breeding interval of females with cubs, of three or more years, since females followed by nursing yearlings have not been seen consorting with a male.

The dens used for hibernation are excavated by the grizzly if natural caves are not available. A den is usually dug on a rather steep slope. The entrance to one I examined was about 2 feet wide and a little less than 2½ feet high. A tunnel 6 feet long led to the chamber which was roughly 4 feet in diameter. Cinquefoil brush and grass had been used for the bed. This den was still usable six years after it was dug. But another den dug in October caved in the following summer. It lacked the firm protective sod roof of the more durable den.

Bears, like humans, enjoy a good back-scratching. Trees along a trail or on some strategic point are much used, as shown by the rubbing signs and the adhering hairs. If trees are not available, willow brush, a boulder or a sod bank may be used. The corner of a log cabin is considered an excellent surface. A pole lying on the ground is a fair substitute, and where no structure is available and a bear feels itchy he may lie on the ground with all four feet in the air, wriggling ludicrously with excessive energy to do the job.

Generally the grizzlies wander freely over the tundra. But they are not averse to taking advantage of a convenient trail when they have a definite destination. Trails that are much used by bears, such as we sometimes find along the bank of a river or through a woods, show a series of worn depressions. These depressions are due to the grizzlies’ tendency to step in the same tracks. They no doubt have been formed by the passage of many bears over a long period. Pieces of such bear trails may be seen a half mile above Teklanika bridge and a short distance below the bridge, on the west side of the river bar.

The grizzly has survived in only a few states, more by accident than by our planning for his future. In Alaska we have a great opportunity for giving the grizzly and the rest of the fauna ample room for carrying on their living in a natural, free manner. The grizzly needs extensive wilderness country for his way of life, and wild country is also vital for the highest development of human culture. If we provide for the future of the grizzly, we at the same time provide wilderness for our own needs.

Black Bear _Euarctos americanus_

The black bear is widely distributed in Alaska. In the park it is confined to the forested areas along the north and east boundaries. I have occasionally seen one near the Nenana River and in the Wonder Lake area I have seen them 3 or 4 miles north of the park feeding on blueberries.