Fauna Series No. 3

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

Mammals

DESCRIPTIONS OF MAMMAL SPECIES

ALASKA MARTEN
Martes americana actuosa [OSGOOD]

GENERAL APPEARANCE.—A mammal the size of a small house cat. The face is sharp-pointed. The color is golden brown and the animal has a large orange-colored patch on the throat. The feet are dark brown and well furred. The toe pads are small and the claws are sharp and curved. The length of the head and the body is 16 to 20 inches. The tail is bushy and about half the length of the body, being from 7 to 10 inches long. The ears are erect, 1-1/8 to 1-5/8 inches high.

IDENTIFICATION.—A distinctive badge of the marten is the broad orange-colored throat patch. The mink is the only animal likely to be confused with the marten. The fur of the marten is longer and fluffier than that of the mink. Too, the mink lacks the orange throat patch of the marten.

DISTRIBUTION.—It was formerly common in the heavier spruce timber of the region but it is greatly reduced in numbers now—due to excessive trapping—so that it is very scarce even in the park. Former Chief Ranger Nyberg reports seeing the tracks of only one marten in the park during the winter of 1926. In 1932 I saw a number of marten pelts. These animals had been trapped on Eldorado Creek just outside the park.

HABITS.—The pine marten is often called "American sable." Because of its rarity, small size, and secluded habits it is not an animal that is frequently seen. Furthermore, it is largely nocturnal and lives to a considerable extent on mice and rabbits. Martens are of an exceedingly nervous temperament and are quick as a flash. Unlike the weasel they rarely kill more than is necessary to supply their immediate needs.

The real home of the marten is in the heavier stands of spruce timber located along the larger streams outside of and below the park for the most part. At present the species is still rare in the park, but there is evidence that it is breeding up and becoming more plentiful in certain timbered sections within the park boundaries.

ARCTIC WEASEL
Mustela arctica arctica [MERRIAM]

GENERAL APPEARANCE.—Weasels have long slender bodies and short legs. The head is small. The ears are short and the tail is round and tipped with black. The black-tipped coloration of the tail is not subject to the seasonal change which is characteristic of the rest of the pelage. The Arctic weasel is brown in summer and, except for the tip of the tail, like the ptarmigan and varying hare, is pure white in winter. The measurement of the male Arctic weasel is: Length, 16 inches; tail, 3 inches; hind foot, 2 inches.

IDENTIFICATION.—The snaky form, the small size, and the black-tipped tail are outstanding characters of the weasel.

DISTRIBUTION.—Weasels are found over most of North America. The Arctic weasel is found on the tundra and along the Arctic Coast. Their local distribution is governed largely by the presence of mice which comprise the chief food supply of the Arctic weasel.

HABITS.—In Mount McKinley National Park there is a close relationship between the numbers of mice and of weasels. During periods when mice are abundant, weasels as a result of this plentiful food supply breed abundantly. Then when there is a scarcity of food in winter due to the disappearance of the hordes of mice, the weasel population becomes greatly reduced probably because of food shortage leading to starvation and faulty reproduction.

A few weasels, scattered over large areas, manage to live through the lean years when the mice are scarce. In 1932, such a lone weasel made his home at the main warehouse at Park Headquarters. By making inquiry among the rangers the fact was revealed that during the previous fall many mice had been attracted by the hay, grain, and other foodstuffs that were stored in the warehouse. The weasel in turn had been attracted by the mice and had spent the winter in and about the warehouse and other nearby buildings.

This weasel had been specially protected by the park officials because he had been able to keep the mouse population in check about the buildings. On May 19, when I first made the acquaintance of this animal, he was in full brown summer pelage without any trace of the white winter coat. This weasel was not afraid of human beings but had a decided distrust of the camera so that it was not feasible for me to get any photographs of him.

At one time when we had him cornered under a pile of old boards he stuck his head out through a crack and with his mouth open uttered a sharp, high-pitched scream of great penetration.

ALASKA MINK
Mustela vison ingens [OSGOOD]

GENERAL APPEARANCE.—Minks are long-bodied, short-legged aquatic weasels. They are somewhat smaller and more slender than a female domestic cat. The tail is moderately bushy and about half as long as the body. The general color is a dark glossy brown with occasional small white spots on the throat and under parts. The adult male minks are half again as large as the adult females. Measurements of adult male Alaska minks are as follows: Length, 29 inches; tail, 7.2 inches; hind foot, 3 inches.

IDENTIFICATION.—The Alaska mink is the largest living race or species of mink in America. The size alone is usually diagnostic. They are some what lighter in color than the Pacific mink which ranges along the coast of British Columbia, Washington, and Oregon.

DISTRIBUTION.—Minks are found along streams and watercourses over nearly all of North America. The Alaska mink is found over most of the western portion of Alaska. In Mount McKinley National Park they are found chiefly around ponds and along the larger streams.

HABITS.—The only specimens of mink from the McKinley region that we have been able to examine were a pair of fine pelts of this species which John E. Anderson had collected near Wonder Lake in an area which was then just outside the north boundary of the park. This area has been added recently to the park. These pelts showed clearly the large size and characteristic color of the Alaska mink.

In 1932, I found some old mink signs in this same locality; however, at best, mink are rare in the park.

MOUNT McKINLEY WOLVERINE
Gulo hylaeus [ELLIOT]

GENERAL APPEARANCE.—The wolverine is the largest member of the weasel family. It has a sturdy bearlike form with short, powerful legs and a bushy tail about one-fourth as long as the body. The feet are semiplantigrade and are armed with powerful curved claws which are light-colored and semiretractile.

The pelage or coat of the Mount McKinley wolverine is long and coarse with a thick fine under fur. The general color of the animal is dark brown. It has a broad pale yellowish-white stripe that extends from the shoulders along both of its sides; these stripes unite at the base of the tail giving the living animal a peculiar streaked affect. Examination of the pelts of wolverines caught near Mount McKinley Park during the winter of 1931 showed that hylaeus is indeed a dark race. This was also true of a living wolverine observed by me at close range on May 21, 1932, in Savage River Canyon.

A large male Mount McKinley wolverine killed by Charles Sheldon near Polychrome Mountain, March 11, 1908 (1930, p. 314), measured: Length, 43-5/8 inches; tail, 8-9/16 inches; hind foot, 7-1/2 inches; height, 15-3/4 inches.

IDENTIFICATION.—Upon meeting a wolverine under natural conditions in the wilds I was impressed with the following field characters: The robust bearlike form and dark color of the animal, which suggested a porcupine; the broad whitish-yellow band extending along the sides and meeting over the rump, definitely identifying it as a wolverine; and finally, a trait which showed the animal's direct relationship to the weasel family, its poise in posture as it stood straight up on its broad hind feet so as to get a better view of me.

DISTRIBUTION.—The wolverine is found throughout Alaska and northern Canada. It was formerly found in the northern United States but now has been exterminated over much of its southern range. Hylaeus is found only in Alaska in the region of Mount McKinley and is distributed throughout the park.

HABITS.—Many people have written about the strange habits of this animal but probably not one in ten of these writers has ever seen or had the experience of meeting a wolverine in the wilds. They have drawn largely upon the stories told to them by trappers and others. As a result, much legendary information—which has never been verified has been published about the wolverine. Therefore it is deemed especially important that unbiased observations made by trained men be recorded in detail and be made available to the public.

Charles Sheldon, an accurate observer, has faithfully recorded many personal experiences with wolverines in the Toklet region in 1906-08.

In 1932, I made a special study of the ecology of the wolverine in Mount McKinley National Park and had an unusual encounter with an individual of the species in its native habitat.

The wolverine like the timber wolf is naturally cautious about approaching any strange object and Charles Sheldon (1930, p. 301) states in referring to a female wolverine that he captured alive, "She possessed keen quick sight, and many tests proved that her power of scent was as strong as that of a wolf. She had no fear of dogs. . . . She would carefully avoid any strange object, . . . never approaching it without suspicion and caution, and never touching it." This trait of the animal to avoid strange objects accounts for the difficulty some collectors have had in trapping wolverine. We have known instances where a wolverine becoming familiar with traps and apparently losing all fear of them would spring the traps repeatedly and always manage to escape itself.

Wolverines do carry off, or eat on the spot, the animals which they find caught in traps and they can eat a prodigious amount of meat or of other food in a relatively short time. Because of this latter fact the animal is merited with the well-earned name of "glutton." Apparently the great amount of food that they can consume at one time is a natural adjustment to conditions regulating the ability to exist in the far north where one day may mean a feast and the next day a famine. In 1913-14, when I spent a winter "frozen in" on the shores of the Polar sea of northern Alaska, I found that the native Eskimos, in 36 hours—comparable to the gluttonous wolverines—could consume large amounts of fresh walrus or seal meat and that they could go foodless then for several days without serious discomfort. Sheldon's female wolverine consumed the entire carcass of a silver fox in one night.

During March 1908, Sheldon (1930, p. 300) noted a trail coming down to the river bar from a point high up in the rocks. It had been made by a wolverine transporting a sheep, apparently large pieces at a time, to a spruce thicket at least a mile and a half from the place where the sheep had died. Sheldon thought the sheep was one which had been wounded here by hunters two days before. Numerous pieces of skin and bones and bits of frozen grass from the paunch of the sheep remained, as well as several large frozen balls of solid meat that had been gnawed into globular form. From the great quantity of excreta the wolverine had continually evacuated, Sheldon believed it must have consumed an incredible amount of meat in a short time. Although wolverines are known to drag their kill for some distance before devouring it, Sheldon states (1930, p. 293) that the malicious destruction of property, such as the carrying off of empty traps, is doubted since reliable proof of such actions has not been forthcoming. He says that these stories are probably products of the imagination.

Repeated observations both by Sheldon and myself indicate that wolverines travel widely yet tend to follow regular routes. This tendency was especially noted by Sheldon on the Toklat in winter. He found trails of four different wolverines in the snow in localities 10 to 15 miles apart. He watched these trails throughout the winter and wolverine tracks of similar size appeared near his winter cabin on the Toklat every "8 or 9 days." From this fact he concluded that wolverines travel periodically over regular routes.

Sheldon reports (1930, p. 294) that a female wolverine when chased by his dogs readily climbed to the very top of a spruce tree. He states, "She climbed so easily . . . that no one seeing her could doubt that wolverines are accustomed to climbing trees." However, of all of the wolverine trails that he followed through the snow this is the only instance of a wolverine climbing a tree that he records. We have been unable to find evidence that wolverines make a regular practice of climbing trees unless they are hard-pressed.

The wolverine is not generally regarded as an animal of clean individual habits, but Sheldon found that the female which he captured alive was very cleanly, depositing feces in selected places and where possible, covering her dung each time.

As I was climbing up a steep snowslide at 10:20 o'clock on the morning of May 21, 1932, I suddenly came face to face with a large male wolverine which was coming down the slide. The surprised wolverine stood straight up on his broad hind feet. He looked like a huge black weasel as he stood thus poised in order to get a better view of the stranger who barred his trail but 30 feet away. He was accustomed to yielding the right of way only to the big brown and the grizzly bear and he stood his ground uttering a low, throaty, and menacing growl. (The female that Sheldon captured likewise growled when cornered. He stated (1930, p. 292) that she also made a "whistling chatter" upon the close approach of any person.) As I gazed into those unflinching black eyes I was not at all sure whether the wolverine or I would do the running, but I stood the suspense longer than did the wolverine which finally ran past me down the slide. By following the wolverine's back trail I found clear-cut hind foot tracks of the animal which measured 7-1/2 inches in length and 4-1/2 inches in width.

The relation of the wolverine to other animals is varied and interesting Sheldon reports (1930, p. 258) that near the north base of Denali on January 1, 1908, "The fresh track of a wolverine crossed the snowshoe trail and was followed for some distance by that of a fox." I found that during the winter along the extreme northern coast of Alaska each polar bear is not infrequently followed over the ice at a respectful distance by a white fox which lives on the scraps of seal left from the bear's catch. In like manner it is believed that an Alaskan red fox may at times follow the trail of a wolverine in order to gather any small bits of food which may have been left by the wolverine. On another occasion, on January 5, 1908, Sheldon watched a Canada lynx feeding upon the carcass of a mountain sheep. Upon the approach of a wolverine the lynx left the carcass. In his report of the incident Sheldon concluded, " . . . evidently the relation of lynx to wolverine is one of fear."

During his hunting trips in the Mount McKinley region Sheldon found ". . . that the wolverine is completely at home among the crags."

On November 17, 1907, Sheldon followed the tracks of a wolverine but he saw no evidence of mouse or squirrel hunting, for the trail continued without interruption. However, he reports seeing a wolverine on March 2 which appeared to be hunting mice. On March 11, 1908, Sheldon killed a wolverine near Polychrome Mountain and upon examining the stomach contents of the animal he found it to contain: ". . . the feathers of a ptarmigan and the remains, including two tails, of ground squirrels." Sheldon states that he does not believe it possible for the wolverine to dig the squirrels out of the frozen ground and that it is, he believes, more likely that some of the squirrels had been lured out of their winter dens by an early spell of warm weather at which time they were captured by the wolverine.

In certain instances Sheldon found from following wolverine tracks in the snow that the animal had kept under cover when traveling or hunting food. It is believed that this action is for offensive rather than for defensive purposes.

Sheldon (1930, p. 310) reports a band of mountain sheep and at the same time the fresh tracks in the snow of a wolverine. He concluded: "It is not improbable that the animal was following and hunting the sheep."

A study of the carcasses of mountain sheep indicates whether the sheep have died slowly of starvation or disease in winter and have been found and eaten by bears or by other carnivores the following spring or whether the sheep have been killed by wolves or wolverines and eaten while the meat was yet fresh. In the former instances there are no blood stains whereas in the latter evidences of blood, stained pelage can usually be found.

There has been and is strong feeling in the West against the wolverine because of its destructiveness to animal life and to human property. However, it should be remembered that the wolverine is an important member of the native fauna of Mount McKinley National Park and as such is entitled to a continued existence there. It is our belief, based on years of field investigation of the fur-bearers in the West, that the wolverine is in serious danger of extermination. Outside of Alaska, we have recent dependable records of the existence of wolverines in only two or three of our other national parks. Even in these protected areas the status of the wolverine is not believed to be at all secure. We further believe that our national parks are the only areas where these animals can find a permanent and sure sanctuary.

Upon personal investigation, Mount McKinley National Park out of all of our national parks appears to be the only one now which has a good breeding stock of wolverines as well as a sufficient range, food supply, and natural habitat to assure the future perpetuation of this vanishing species.

CANADA OTTER
Lutra canadensis canadensis [SCHREBER]

GENERAL APPEARANCE.—River otters are large aquatic weasels with long slender lizardlike bodies and long tapering tails. This animal has short powerful legs and claws. The feet are webbed and admirably adapted for swimming. The under fur is short and well protected by numerous strong glistening guard hairs. The pelage of the otter is very dense and the pelt makes a most durable fur. In color the animal is a uniform rich glossy brown above and a somewhat lighter brown beneath. The lips and cheeks of this otter are grayish. Size, large; length, 44 inches; tail, 14 inches; hind foot, 4.5 inches.

IDENTIFICATION.—The only other aquatic animal with which the river otter is likely to be confused is the beaver which has a wide flat scaly tail and a sturdy corpulent body. When the two animals are swimming and their bodies are submerged, the otter can be distinguished from the beaver by its more rounded or spherical shaped head. Another means of distinguishing one from the other of these two animals is by noting the actions of each species when alarmed. The otter dives quietly or sneaks off while the beaver whacks the water with his tail.

DISTRIBUTION.—River otters were formerly found in most of the larger rivers of North America but they have disappeared from many of the populated regions. In the McKinley region a few otters still occur along the larger rivers.

HABITS.—Otters are great wanderers. As has been stated their real habitat is along the larger streams where fish are abundant; however, at times they invade the small lakes and ponds bordering the northern boundary of the park and signs of them are reported from time to time within the park.

Mr. and Mrs. John L. Anderson, who resided for many years at Wonder Lake, recently assured me that otters were definitely known to occur in the area which was formerly outside the park along the north boundary near Wonder Lake. This area has recently been added to the park.

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Last Modified: Thurs, Oct 4 2001 10:00:00 pm PDT
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