DESCRIPTIONS OF MAMMAL SPECIES
NORTHERN HOARY MARMOT
GENERAL APPEARANCE.The northern hoary marmot is the northern representative of our common ground-hog or woodchuck in the States. It is a large, chunky rodent with strong black claws which are adapted to digging. Its tail is bushy and is less than half the length of the animal's head and body. The forward half of the hoary marmot is a clear, grayish-white but the hind part and tail are tinged with brown, particularly on the belly, rump, and tail. The ears are small and round, scarcely extending above the hair of the head (fig. 53). The feet are black.
Alaskans call marmots "whistlers" from their habit of announcing an enemy's presence by uttering a shrill, piercing whistle. Length, 27.5 inches; tail, 7.5 inches; hind foot, 4.1 inches; ear from crown, 0.7 inch.
IDENTIFICATION.Northern hoary marmots are the largest rock inhabiting rodents in the park. Their chunky build, gray shoulders and almost black areas on the top of the head, together with their piercing "traffic-cop" whistle, make their identification easy.
DISTRIBUTION.Marmots are rock dwellers and rarely stray far away from sheltering granite boulder piles. We found that the Savage River Canyon, about 3 miles below the main transportation company's camp and along upper Igloo Creek, were the best places to look for them, for at one time we found as many as a dozen in one day. In McKinley Park marmots were found, for the most part, between elevations of 3,000 and 4,000 feet.
HABITS.Under ordinary circumstances hoary marmots are usually seen on the top of boulder piles. However, during late spring while the females are nursing their young the male marmots sometimes wander from a quarter to a mile away from home. Thus on May 19 near the cabin on Savage River we came upon a large male marmot that was fully 400 yards from the nearest protecting rock slide. He was probably foraging for new pastures and, being taken by surprise, galloped down the road ahead of us. He loped along at about 5 miles per hour. When hard pressed he left the road, took refuge in a galvanized iron culvert under the road and refused to be driven from his safe retreat, although he stuck his head out now and then to see what the rumpus was all about. On May 27 we found a family of marmots in a boulder pile at 3,500 feet elevation (fig. 54).
At one time a male rock ptarmigan, a cony, and two marmots were all sunning themselves together on top of a rock pile less than 50 feet square.
Marmots have numerous enemies with which to cope. Several times we found golden eagles in the act of swooping down upon unwatchful ground hogs. On June 12, 1932, at Double Mountain, the remains of a hoary marmot were found in a golden eagle's nest. These birds of prey appear to prefer half-grown marmots, while bears, wolves, and coyotes not infrequently capture the larger adults.
The young marmots are born early in May and half-grown young were observed on June 5. As soon as the young are able to be out, the clear "traffic cop" whistle of the old marmot is usually heard whenever a person approaches a rock pile that is inhabited by them. One old marmot that I watched crawled up on the very summit of a gigantic boulder. There he flattened himself out in a depression and lay concealed so that just the top of his head, including his eyes, showed above the rock. As he lay watching us his gray coat blended so well with the gray granite rock that he appeared to be merely a part of the boulder. By June 10 nearly all of the marmots have well worn paths leading from the dens in the rock piles down into the meadows which are then becoming rapidly clothed with green vegetation.
Once in a great while a marmot goes adventuring and wanders far from home. Thus at 8 o'clock on the morning of June 9, we discovered a large male marmot about a pile of logs near camp. He must have come a long way because it was more than a mile to the nearest known marmot den. When he first saw us, he took off up the hill and, as he had a 50-yard start, we ran a distance of more than 300 yards before overtaking him. He then tried to escape detection by lying motionless, stretched out at full length. Finding that this ruse failed to work, he stood his ground on the open tundra. Here, with neck and tail extended, he fought with tooth and claw giving frequent shrill warning whistles. After taking several pictures of him (fig. 53), we watched him scurry back to shelter.
By the time the heavy fall frosts blacken the growing herbage, the marmots have lined their underground nests with shredded plant fibers and dry grass. When the snow falls they retire to their homes in the rocks where they spend the winter in hibernation. The following spring, the marmots come out of these winter nests while the nearby snowbanks still blanket the ground. Immediately upon leaving their dens these animals discard the grass lining of their winter homes (fig. 55).
The Indians of interior Alaska catch many "whistlers." They use the meat for food while the pelts are tanned and made up into fur robes and bedding.
Unlike varying hares, lynx, and mice, the marmot population of Mount McKinley National Park appears to fluctuate but slightly from year to year. Marmots may be found in fair numbers in suitable locationssuch as Savage River Canyoneach season.
NUSHAGAK GROUND SQUIRREL
GENERAL APPEARANCE.A fat chunky prairie dog-like squirrel weighing about 1 pound and measuring 10 to 12 inches from the end of its nose to the base of its tail. The tail is short, flat, and bushy, being less than half the length of the body. During the spring and fall the general coloration of the animal is grayish, but in the summer it becomes a rusty color on the forehead, cheeks, forelegs, hind legs, and under parts. The ears are very short (fig. 56). Length, 12.8 inches; tail, 3 inches; hind foot, 2 inches; ear from crown, 0.2 inch.
IDENTIFICATION.When alarmed this squirrel has a habit of sitting straight up like a stick or picket pin (fig. 56). At close range the plump body, short tail, small compressed ears, and the small white specks on its lower back distinguish it at once. This ground squirrel is the noisiest mammal in the park.
DISTRIBUTION.It is distributed generally over the higher ground at the base of the Alaska Peninsula and along the Nushagak River, being most abundant just above timber line on warm, open, grassy hillsides in nearly every section of the park between 2,000 and 6,000 feet elevation. The Transportation Company's Camp on the Savage River is an excellent place to see ground squirrels.
HABITS.The ground squirrels in the park hibernate during the winter. Charles Sheldon saw the last ground squirrels of the season at Toklat River on October 2, 1907. The first Nushagak squirrel reappeared the following spring on April 10.
By April 30, these squirrels usually begin to breed. On May 26, the first female was seen carrying nest material. On this occasion she was noted tearing an old grain sack to pieces with her teeth and dragging the material into her nest under the ground. Three females which were killed on June 20 had each given birth to their young. On June 21 a squirrel was seen tearing an old strawboard box to pieces. It stuffed the material into its cheek pouches and carried the material to its burrow where it was used to make a nest. Nest renovation goes on after the young squirrels are born and it is not unusual to see a nursing female squirrel carrying bulky loads of dead grass, shredded bark or other dry vegetable material down her burrow and into the nest.
Ground squirrels have large litters of from five to eight young. Practically all of the young squirrels were born before June 30. Early-born young squirrels, nearly one-third grown, were seen running about by July 4.
Ground squirrels are particularly abundant at Sable Pass and at the head of Savage River. This was attested by the animals themselves and by numerous little craters left by grizzly bears where these carnivores had dug out the squirrels. Golden eagles levy a heavy toll on the squirrels as do also red foxes and other fur-bearers. It is our opinion, taking all factors into account, that the ground squirrels are the most important food supply of the meat-eating birds and mammals in the park. Daily, during the latter part of June, we counted more than 100 adult squirrels on an area half a mile wide and 2 miles long. This meant 50 families of squirrels per square mile by late summer. At the caribou camp on upper Savage River we found that more than 15 squirrels made their homes within a hundred yards of our tent.
Residents of Alaska call the ground squirrels "parka" squirrels because the natives prize the skins of these animals for making their summer "parkas" or coats. The parkas differ from our coats in that they usually have a hood attached and are made of reindeer skins. Too, they do not button down the front but pull on over one's head like a "slip-on" sweater.
"Parka" squirrels are exceedingly noisy, especially so when any winged or 4-footed enemy, such as an eagle or a grizzly bear, appears on their horizon. Visitors to the park will find that "parka" squirrels are quick to make friends with man and that they do not hesitate to exploit this relationship. Nothing edible is safe if left on the ground unless stored in metal squirrel-proof containers. Even the grizzly bears do not go through a poorly protected cache of food supplies more thoroughly than do the "parka" squirrels.
Much of these squirrels' time is spent in scolding and fighting among themselves. A good deal of this is bluff, but on occasion they stand up on their hind legs and fight "tooth and nail."
The red summer coat appears first on the head, then on the feet and back. By the 20th of July much of the gray winter pelage has been replaced by the red summer hairs, giving the squirrel a very mottled appearance (fig. 57). Even in late summer young ground squirrels of that season can be distinguished with ease from the adults by their paler, grayer color and softer downy coat.
Young ground squirrels are very greedy. At Igloo Creek camp on July 21, a red squirrel and a young ground squirrel were observed fighting over a crust of bread that had been thrown out. The red squirrel found the bread first. Then a young ground squirrel came along and made him drop it. A lively scramble ensued. The more active red squirrel ran in like a flash and knocked the ground squirrel over in an effort to drive him away. The ground squirrel was so busy eating that he did not take time to fight back; he continued to stuff himself with bread (fig. 57) until the last crumb was consumed. The red squirrel, on the other hand, ate a little bit of his crust. Then he scampered away and hid the remainder at different places in a spruce tree, usually placing bits of it out near the tip of a branch in a cluster of needles well out of the reach of the nonclimbing ground squirrels and other rodents.
By the end of summer the ground squirrels become fat and lazy. The first real snowstorm in the fall finds them safely tucked away in their warm beds underground where they soon pass into a deep hibernating sleep which lasts through the entire winter. They are not seen again until the following spring when the bare ground begins to show through the snow.
In the spring when they again appear some of these hardy ground squirrels dig their way up through several feet of snow. They use their stout claws which are long and sharp when these animals first emerge from hibernation.
Contrasting the population of ground squirrels to that of varying hares, apparently the former population does not fluctuate so greatly from season to season as does that of the latter. The ground squirrels are an important food supply for grizzlies, fur bearers, and certain birds of prey.
NORTHERN RED SQUIRREL
GENERAL APPEARANCE.The body is about the size of an ordinary Norway rat. The tail is nearly as long as the body and is flattened and plume like. The upper parts of this squirrel are grayish in winter and reddish in summer; the under parts are lead color in winter and yellowish white in summer. The ears are well-tufted with hairs in winter but are only slightly so in summer. It has a distinct black stripe along the lower middle part of the sides in summer. The claws are compressed, sharp, and curved and are well adapted for climbing. Length, 12.5 inches; tail, 4.5 inches; hind foot, 1.9 inches.
IDENTIFICATION.The tree-climbing habits, feathery plumelike tail, small size, reddish color, black stripe on the sides, and the white ring about the eyes (fig. 58), distinguish this squirrel from all other rodents in the park.
DISTRIBUTION.Red squirrels inhabit the coniferous forests of boreal North America. The northern red squirrel is found throughout the park wherever there is a suitable growth of spruce trees. The camp of the transportation company on Igloo Creek is a good place to study this animal. Red squirrels may also be found in the spruce woods just back of the main camp of the transportation company on Savage River. At this latter place we found them numerous throughout the summer of 1926.
HABITS.Without the lively northern red squirrel the silent spruce woods of the North would lose much of their charm. The well known "chirr" or "trill" note of the red squirrel is one of the most characteristic sounds of the spruce woods in the park. These trees provide shelter and a safe home for the red squirrels during the stressful freezing storms of winter. The seed contained in the cones of the spruce tree is the staff of life for the red squirrel. Visitors to Mount McKinley Park frequently find the compact nests of this animal which are made of fibrous roots, moss, and shredded bark and are placed well up in the trees, and they mistake them for the nests of birds. One should not be blamed for making such a mistake because in location, size, and construction the nests are very similar to those built by birds except that the squirrels' nests are originally roofed over while the birds' nests are open.
A typical northern red squirrel nest was placed 16 feet up in a dense spruce tree. This nest was globular in shape and was 12 inches in diameter. Its walls were 4 inches thick and were made of twigs, leaves, and moss. A single hole through the side of the nest led to the inner cavity which was lined with the hair of the mountain sheep. Another nest was lined with caribou hair and ptarmigan feathers.
The red squirrel does not hibernate in winter as does its relatives the "parka" squirrel and the Northern hoary marmot. Instead, he is active during suitable weather throughout the winter season. It is true that during cold snaps he may retire to his warm nest for several days at a time, but such retirements are merely temporary and the squirrels are abroad again as soon as the weather moderates.
The red squirrels of the park have appointed themselves on the reception committee. They are among the first of the numerous animals in the park to make the acquaintance of visitors. If the visitors are backward, the red squirrels are willing to meet them more than halfway, even to the extent of coming into their camp at 3:30 in the morning to see what the strangers are going to have for breakfast. A picture was secured (fig. 59) of a friendly red squirrel that was bent on this very mission one morning. However, at times these squirrels have serious competition to cope with in their work of camp investigation. Their competitors are the Alaska jays which are commonly known as camp robbers. As previously described, on June 1, while we were camping in an old tent on the upper Savage River, we watched a red squirrel chase a pair of Alaska jays away from the tent. Every time a jay would alight in the top of a spruce tree near the camp the squirrel would look up at him for a moment and then, picking out the tree the bird was in, he would run up the spruce and jump at the jay in an effort to drive the intruder away. Frequently, just before the squirrel reached the jay the bird would hop or fly across to a nearby tree. The squirrel would then run out to the end of a branch and jump across to the adjoining tree, sometimes clearing between 4 and 5 feet at a leap. If the tree was so far away that it was impossible to bridge the gap by jumping, the squirrel would go down to the ground and then again single out and climb the tree where the bird was perched.
In seeking for an explanation of this unusual behavior we continued to watch the squirrel for several minutes after the bird had departed. The jay had not been gone more than 5 minutes before the squirrel was observed to remove some of his stored food, a piece of old cheese which we had thrown away, from a cache in one of the treetops. We thought that he showed considerable intelligence because he hid it in a hollow log where the jays would be much less likely to venture. It may have been professional jealousy between the robbers or, more likely, the squirrel was simply trying to drive the jay away from his stored food.
Red squirrels are sometimes very destructive to blankets and bedding which of necessity are kept stored in the ranger-patrol cabins along the park boundary line. When the ranger is absent on patrol duty these squirrels often get into the cabin by gnawing their way through the moss chinking between the logs that form the cabin wall. Once inside, they proceed to carry off all the portable food supplies, such as rice, dried fish or meat, and dried fruits. However, the greatest destruction is inflicted upon the bedding, which unless it has been carefully rolled up and hung by wires from the rafters, so that the squirrel cannot reach it, is torn to pieces and the inner filling, consisting of cotton, wool, or down is carried off by the squirrel to be used as a lining for his own winter nests, of which he usually has several. The squirrel's nests are well hidden under the dense drooping branches of protecting spruce trees which, in this instance, were located near the cabin. On one occasion a Northern red squirrel was known to have destroyed more than a hundred dollars worth of food and bedding in a few weeks. Food supplies and blankets can be protected by hanging them out of reach or storing them in squirrel-proof chests.
During excessively cold winters and in seasons when the crop of spruce cones is light the Northern red squirrels diminish in numbers. Since they are active all winter they run a continuous gauntlet of danger because of their enemies, for they are preyed upon by hawks, owls, martens, foxes, and Canada lynx. However, in spite of this, the red-squirrel population remains fairly constant from one season to the next.