Part 2

This country provides an extensive summer sheep range in the high rolling tundra and rugged peaks above timberline, in addition to a large wintering area in the lower timber and valleys. Strong winds in the winter sweep snow from the scant tundra vegetation and often make it possible for sheep to feed at these high altitudes even during the winter months. Even with these adequate topographic conditions, wild sheep in the National Park since 1922 have shown a slow, steady decrease in numbers until 1941, when there were about 300 sheep present. Since this date there has been a leveling off of sheep numbers, no decided increases or decreases being evident. All the related factors probably contributing to the decline of bighorn population or their present stability at low level are not known. One substantial reason advanced has been the deficiency of mineral in sheep diet in the higher mountains, as indicated on previous pages, with a resultant weakening of sheep stock and a consequent susceptibility to parasitism and diseases found prevalent among sickened and dead sheep over a period of years. Another possibility for the decline may be present in the great increase of elk and subsequent competition for similar grass foods. The Park Service has placed salt and mineral blocks at known bighorn concentration places in an attempt to improve the physical condition of the sheep and thereby increase the sturdiness of their offspring. The results of this experiment are difficult to measure, but it is believed to have met with varying success.

BEAVER PROBLEM

The beaver, being a versatile and adaptable animal, is able to establish himself wherever there are small, permanent streams and sufficient aspen to provide him with logs and twigs for dams and houses and to provide food for his family. Consequently, any of the valleys in the Park which supply these requirements now contain numerous beaver. They represent more of a nuisance factor than a real game management problem. Occasionally they will inundate and drown aspen stands and associated vegetation. Also, their dams will cause flooding of roads or other man-made improvements. Infrequently their dams are dynamited to release these waters and the beaver are live-trapped and transported to "wilder" areas in the state. Beavers were so numerous in the Park in 1941 that 106 were live-trapped and taken by state conservation officials to other Colorado areas. The fact that beavers work chiefly at night and have no serious predation worries has helped their normal increase.

These wildlife management problems are but samples of similar situations occurring throughout the country, but in varying degree and with different animals. These are types of conditions which wildlife managers must face. It is evident in the National Park that suitable study and research on such factors as animal-mineral requirements, parasites and diseases, bighorn-elk competition for food, rodent and big game food competition, condition and availability of winter foods, and predator relationships are vital to properly reconcile the use of the same area by man and various wildlife.

Animal populations are rarely in an "ideal condition of balance" in the same area. Rather, the normal condition is a series of population waves or fluctuations either increasing or decreasing the total numbers of a kind of animal. While some exhibit a kind of regularity, they do not always occur with definite rhythm or in exact cycles. This was probably true in nature before the arrival of white man and will likely exist in wilder areas with little modification by man.

Another condition which must be considered normal among animals is the practice of predation, or killing of one kind of animal by another. The predator should be given the same opportunity to live its normal life as are the greatly favored species.

More often than not the predator takes the weakened or diseased animals of an area and thus aids in preventing the diseased animals from roaming among their fellows and spreading the ailment. Nature's sustaining law requires only the survival of the fittest and the predator fits admirably into this scene, unless he becomes too abundant.

The fear of wild carnivores or the "unknown" at night in the mountains is still somewhat prevalent. A comparatively brief knowledge of animal habits will soon force the less intrepid to concede that "wild animals" rarely attack a human in the wilderness, unless unduly provoked.

Finally, we should contemplate the wildlife of this country from another than the hunter or commercial aspect. The range limits of some of the more superb animals in America today are shrinking into closely confined areas where the few spots of virgin wilderness remain. Man should direct his efforts toward assisting these grand animals to at least hold their own.

The thrill of close observation of a wild animal in natural surroundings, without the artificiality of bars or fences, is one of the outstanding satisfactions still available to man in this country. This inspiration and enjoyment, provided by the study and practice of wildlife preservation in the national parks, is of great importance as an intangible, but powerful influence on personal and national well-being.

LIFE ZONES AND ANIMAL DISTRIBUTION

Two interpretations governing the vertical distribution of plants and animals in the western mountain regions have been developed in the past years. Both are based on the premise that definite plants and animals (known as zone indicators) have maximum and minimum altitudes, above and below which they are unable to survive. The net effect is to group these plants and animals into belts or zones on mountain slopes, which vary but little in elevation above sea level throughout the western United States. The reasons why increases or decreases in mountain elevation so markedly affect the distribution of plant life, and to a much lesser degree the animal life, are closely correlated with the differences of temperature, available moisture, wind velocity, exposure of area to sunlight, soil, and topographic variations existing between these zones. Temperature in particular, being an easily measurable difference, has been used by Merriam in his classification of life zones. He computed the mean annual temperatures and made temperature summations for each clearly recognized zone of plant and animal life; he found that for each 1,000 foot rise in elevation there was a corresponding decrease in temperature of 3° F. Based on these temperature differences, definite geographical belts were formed and given names--arctic-alpine, hudsonian, canadian, transition and sonoran zones. Although in current use throughout the west, these zones are not clearly separable in the north-central Rocky Mountain region of Colorado, and therefore are not used here.

Weaver and Clements, following the same general idea, but considering all of the various factors mentioned above, devised a classification of zones which is applicable to the Park mountains and will be mentioned below. Actually, the trees and smaller plants fit very well into these zones, but animals, because of their mobility and wide adaptibility, can hardly be classed in any definite zones. Most animals range at various times of the year through all three zones mentioned, but because a few do inhabit certain areas a large part of the time, they are considered to be typical of these zones. Probably the real limiting factor for animal localization is the degree of severe winter conditions they can endure; the more adaptable they are to low temperatures, the higher they may be found in the mountains throughout the year. Of course, the distribution of herbivorous (plant-eating) animals largely determines the range of the predatory animals feeding on them.

LIFE ZONES (Weaver and Clements)

Alpine Zone--Any area above timberline--(About 11,300 feet) Grasses and herbaceous plants

These mammals could live the year 'round here if necessary, but all can and do range into the other two zones below:

Pika Marmot Pocket Gopher Coyote Red Fox Snowshoe Hare Mountain Sheep Long-tailed Vole Dwarf Vole

Subalpine Zone--9,000 feet to timberline--Dense forests of alpine fir and engelmann spruce, with occasional limber pine.

These animals extend but rarely into the alpine zone during the coldest part of the winter, and can and do range into the zone below:

Chickaree Bobcat Marten Cottontail White-tailed Jack Rabbit Dusky Shrew Golden-mantled Ground Squirrel Least Chipmunk Red-backed Vole Porcupine Long-tailed Weasel

Montane Zone--6,000 to 9,000 feet--Predominantly western yellow pine with scattered Douglas fir and aspen trees.

These animals are considered characteristic of this lowest Park zone and rarely wander into the subalpine zone.

Striped Skunk Badger Richardson Abert Squirrel Cliff Mouse Ground Squirrel

All other mammals in the area, not mentioned above, probably range throughout these zones, especially during the summer months. Lodgepole pine may occur in the montane zone, while lodgepole pine and aspen are also abundant in the burned-over areas of the subalpine region. They are classified as sub-climax species and therefore not acceptable as zone indicators. When considering the altitude of timberline, it is important to understand that it will vary as much as 500 feet above or below the average of 11,300 feet, depending generally on the quantities of sunlight received. On warmer south and west slopes, timberline may go as high as 11,800 feet, while on the shaded north and east slopes it may drop down to 10,800 feet.

THE MAMMALS OF ROCKY MOUNTAIN NATIONAL PARK

While the term "animal" is commonly used in speaking of our four-footed wildlife, it is best to record with more complete accuracy that "animals" include any living thing having sensation and the power of voluntary movement. This would therefore admit a great variety of creatures such as one-celled protozoa, worms, fish, frogs, snakes, birds, and finally the four-footed animals mentioned--mammals. Mammals are set apart as a special group of animals for two reasons: they have some sort of hair covering on their bodies and the females are equipped with mammary (milk) glands for nursing their young, features which none of the other "animals" possess.

THE HOOFED ANIMALS

ELK (Cervus canadensis nelsoni)

Much taller and heavier than deer, with a dark brown, shaggy neck mane contrasting with the tan of the body. Large, round, cream-colored patch on rump. No antlers on females (cows). Running or galloping type gait.

A large number of these majestic animals are present in the region. In late June when snows melt from the high country meadows, bands of cows with their calves, may be found grazing in high valleys near timberline, or in the open tundra country above timberline. Cow elk usually bear a single calf each year. The characteristic white spotting on young calves usually disappears by mid-August, whereas deer fawn spots persist into the fall season. Occasionally, a bull will mingle and wander with a band. Large summer herds are often seen on the distant tundras from the Trail Ridge Road above timberline. Hikers have recently reported abundant elk in the extensive, isolated areas north of the Mummy range. The elk remain above 10,000 feet usually until the first week of September, when they migrate to the lower timber and valleys. This is the start of the mating (or "rutting") season, when the bull antlers are being polished and hardened. The challenging "bugle" of the bull elk can then be heard ringing out in a soul-stirring manner. The bulls at this time engage in a series of minor skirmishes with one another, for the purpose of dominating a group of cows (a harem) during the rutting season. Sometimes these meetings develop into mighty battles, with these large, antlered beasts weighing up to 700 pounds apiece, pushing and gouging with their antlers and striking at each other with large front hoofs, until the vanquished flees. This is illustration on a grand scale, of nature's way of providing the strongest animals for breeding and continuation of a strong stock.

Beaver Meadows and Horseshoe Park are particularly good places to view elk in the fall, from an auto. These cautious animals have excellent hearing ability and an exceptionally good sense of smell. They can detect a human a half mile away in proper wind, and once alarmed will retreat immediately to the wooded slopes. At the height of the rutting season, however, the elk are less easily alarmed. When elk can be seen from road parking areas, it is best to remain quietly in the car, as the gasoline odors seem to overpower any human scent they might obtain. Whatever the season, elk are most easily observed when they are feeding, either in early morning hours or at dusk. Often they can be "spotlighted" from the highway after twilight either on the tundra or in the valleys.

MULE DEER (Odocoileus hemionus hemionus)

A stout, chunky-bodied deer with a yellowish-gray coat, turning to gray in winter. Has big ears, small white rump patch; white tail with black tip is held down while running. Has stiff legged, bounding type gait. Antlers on males (bucks) only.

These beautiful creatures are the most abundant and widely distributed large animals in the Park. They may be found singly or in small groups throughout the forest and meadows, during the summer, and often graze at dusk and during the night near the Trail Ridge Road, from 8,000 to 12,000 feet altitude. In early June the females (does) usually bear their white-spotted, twin fawns in the deep forests; while the males (or bucks), having left the family circle, are ranging far and wide in the wilderness. In early October the snows and winds usually drive the deer into the lower regions, where they assemble in small herds. The necks of the bucks begin to swell, heralding the approach of the rutting season, and a series of fights or "tussles" ensue among the bucks for possession of their harems of three to five does. These fights consist of the males horning and pushing one another around for short periods, when the stronger buck will finally throw the other off his feet and gore him with sharp, pointed antlers until he leaves. Mule deer herd together in the winter, feeding on aspen leaves and branches, and pawing away the snow from low bushes and shrubs to obtain their preferred diet. When the snow has melted on the steep south slopes in early June, they break up into little bands and scatter to the four winds.

Mule deer have sharp eyes and a good sense of smell and hearing. However, they have a peculiar sense of curiosity and, if not alarmed, will often approach a spectator quite closely.

The number of points on mule deer antlers is a very poor indication of age. A yearling will usually have a pair of spikes six to eight inches long, but between two and five years of age the antlers may continue to hold the four points (tines). Deer (and elk) antlers frequently deteriorate with age and "go back" to two points or to a freakish number of points, sometimes numbering up to twenty-four points on a head. Very old deer and elk usually have short, scrubby sets of antlers and, of course, all elk and deer males lose their antlers in early spring and start immediately growing a new set. The hoofed animals in the Park are preyed on by cougar, coyotes, and bobcats. The coyote, originally a plains animal, has developed into a stronger and heavier mountain species, capable of bringing down adult deer and the younger elk and sheep.

MOUNTAIN SHEEP (Ovis canadensis canadensis)

A large, grayish-brown sheep with a distinct whitish rump patch. Males (rams) larger; up to 300 pounds, having horns which sweep back and down and finally, in older rams, curling forward. Females (ewes) weigh up to 175 pounds, with smaller horns pointing backward with slight curvature. Ewe horns have a vague resemblance to the mountain goat horns, but there are no wild goats in the southern Rocky Mountains. Mountain sheep are also called bighorns.

No other animal of the Rockies is so symbolic of the wild, rugged grandeur of the Western mountain peaks as the mountain sheep. While they graze on sweet summer grasses and flowers of the alpine meadows and slopes, at 12,000 or more feet altitude, they are truly kings of all the vast domain they survey. They are all the more precious in the sanctuary of Rocky Mountain National Park. It is possible to drive up Trail Ridge Road and if one is ambitious, continue on foot up several miles of tundra slope to see one of the finest animal creatures placed on our planet. There are few places in this country where access to the high mountain peaks and sight of the bighorn is as easy.

The ewes bear their lambs singly, among the crags and rocky basins high above timberline, in late spring. After a few weeks they congregate in small flocks along with the yearlings (and sometimes young rams) to spend the summer in thin-aired solitude. The older rams keep by themselves, alone or in smaller bands. When the winter winds and snows begin whirling around the lofty peaks, the sheep seek refuge in protected cliffs and timber, or even move to lower valleys. The mating or rutting season occurs in November, accompanied by terrific battles among the rams for their harems. The opponents race at each other, leaping into the air for the final, powerful crash of horns, which may be heard a mile away. After a number of such encounters, the smaller or weaker sheep gives up and walks away. The skulls of rams are well adapted to the terrible beating they take in battle. The top front of the skull is double, having a layer of bone, then a space, then another layer of bone surrounding the brain case. In addition, the rams have a one-inch or more layer of shock-absorbing cartilage on the skull in back of the horns, joining the head and the backbone. Ram horns are not lost each year as are the antlers of deer and elk. Rather, they furnish a good indication of the age of the sheep, as they add a definite ridge or ring to the horn in its lengthening growth each fall season.

Bighorn bands have been observed recently in the following areas during the summer: The Never Summer Range, the Mummy Range, Flattop Mountain and peaks in vicinity, MacGregor Mountain, Specimen Mountain, Mount Ida and Sheep Rock, and on the crests near Trail Ridge Road above timberline. The small bands of sheep in the Park will shift with the season and with the year, but the last three named areas probably offer the easiest opportunity for viewing them. Sheep are usually on the move and feeding only in the very early morning hours and evening hours, often bedding down in secluded places in late morning and early afternoon. When stalking them, keep in mind that bighorn's eyes are exceptionally sharp and capable of detecting a moving human up to two miles away. If you can spot them first with a field glass and then keep out of sight until near them, your chances of a good view are much improved.

THE FLESH EATERS (CARNIVORES)

BLACK BEAR (Ursus americanus)

Bulky, heavily furred animal up to 3 feet in height when on all fours. Born with and retains either a black or cinnamon-brown fur. Adults weigh about 300 pounds, sometimes much more.

Although there are an estimated thirty black bear roaming the deep forests of the region, they are only occasionally seen because of their solitary, nocturnal habits. They are infrequently observed lumbering across a road or foraging an outdoor garbage pit in the evening. The latter practice is discouraged, when discovered, to prevent them from becoming "bum" bears. Because of their unpredictable and sometimes vicious manner, it is unwise to feed or make friendly overtures toward any bear. They have only fair eyesight, but in the woods can scent or hear a human coming long before he might be seen, and will slip silently away through the woods, despite their bulk. The heavy, clustered bear dung and large tracks are the most usual sign of bear in the region. The diet is largely ants, grubs, berries, roots, and some small rodents. Bears in the region will den up in early December and go into a light sleep or semi-hibernation, living off their stored fat layers. They may be easily wakened from this sleep. The females, which have mated the previous May, usually bear twin cubs in February. The cubs, strangely enough, are about the size of an adult squirrel when born. They grow rapidly and are soon out in the scattered snow fields feeding with Mama.

MOUNTAIN LION (Felis concolor hippolestes)

Very large, slender cat with small head and long, heavy, black-tipped, cylindrical tail. Fur soft, yellowish or reddish brown. Length, including tail, about 7 feet, height at shoulder almost 2½ feet, weight varies from 100 to 176 pounds.

These great, sleek cats are among the most elusive of all animals to be seen in the wild. Because of their natural wariness and highly developed senses of smell and hearing, few persons have ever sighted the lithe, muscular body. Those who have, usually discover them from a distance, "sunning" on some rocky ledge or cliff. A few cougars are reported inhabiting the small canyons off the Devil's Gulch area, northeast of Estes Park. If true, it is probably these cats making their circle "tour" of 50 to 100 miles in a few days' search of game, that are infrequently seen in the Park. Cougars prefer fresh meat and prey chiefly on deer, but will catch rabbits and rodents occasionally. They have been known to trail a human long distances, but rarely show themselves or attack.

BOBCAT (Lynx rufus uinta)

General appearance like an extremely large domestic cat. There is considerable variation of color pattern in different kinds of bobcats, but the species seen in this area is buffy above with fine streaks of gray and black; black bands appear prominently on legs. Total length about 3 feet; tail 6 inches. Weight up to 25 pounds. Note: The only animal the bobcat might be confused with is the lynx. The bobcat is smaller, buffy rather than gray, has smaller feet and short 1 inch ear tufts. The lynx is practically extinct in this area, while the bobcat or their tracks may be seen occasionally.