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Title: Mammals of the Southwest Mountains and Mesas Author: George Joyce Olin Illustrator: Edward Bierly Release Date: January 1, 2016 [EBook #50822] Language: English Character set encoding: UTF-8 *** START OF THIS PROJECT GUTENBERG EBOOK MAMMALS SOUTHWEST MOUNTAINS MESAS *** Produced by Stephen Hutcheson, Dave Morgan and the Online Distributed Proofreading Team at http://www.pgdp.net Mammals of the Southwest Mountains and Mesas MAMMALS of the southwest MOUNTAINS and MESAS by GEORGE OLIN illustrations by EDWARD BIERLY Hoofed Animals Bighorn (mountain sheep) Pronghorn (antelope) Bison (buffalo) Mule deer White-tailed deer Elk Rodents (Including Lagomorphs) Snowshoe hare White-tailed jackrabbit Mountain cottontail Pika viii ix Uncaptioned Southwest Parks and Monuments Association Box 1562, Globe, Arizona 85501 Copyright 1961 by the Southwestern Monuments Association. All rights reserved. No part of this book may be reproduced in any form without permission in writing from the publisher, except by a reviewer who may quote brief passages in a review to be printed in a magazine or newspaper. Library of Congress Catalog Card Number: 61-11291 SBN 0-911408-32-0 Southwest Parks and Monuments Association (formerly Southwestern Monuments Association) First printing, 1961. Second printing, 1971. Third printing, 1975. Popular series no. 9. Printed in the United States of America Arizona Lithographers · Tucson, Arizona ACKNOWLEDGEMENTS With this booklet, as with Mammals of the Southwest Deserts, we are indebted to Dr. E. L. Cockrum, Assistant Professor of Zoology at the University of Arizona who has checked the manuscript for accuracy. We are also grateful to him for offering suggestions and criticisms which have added materially to its interest. The writer would also like to voice his appreciation to Ed Bierly whose magnificent illustrations adorn these pages. His is a talent with which it is a privilege to be associated. Finally our thanks to the editor and his staff. It is not an easy task to combine text with illustrations, nor to match space with type, yet it has been done with feeling and precision. Together, we hope that you will approve of our efforts. If through this booklet you gain a better understanding of the mammals that share the great outdoors with us, or if through it you should become aware of the urgent necessity of preserving some of our wild creatures, (and wild places), now before it is too late; we shall indeed be well repaid. CONTENTS 1 2 4 8 10 13 16 21 22 24 26 28 Tassel-eared squirrel (Abert’s squirrel) Kaibab squirrel Arizona gray squirrel Spruce squirrel, Pine squirrel (Douglas squirrel, chickaree) Northern flying squirrel Western chipmunks Golden-mantled ground squirrel White-tailed prairie dog Yellow-bellied marmot (woodchuck) Deermouse (white-footed mouse) Mountain vole Western jumping mouse Bushy-tailed woodrat (pack rat) Muskrat Beaver Porcupine Northern pocket gopher Carnivores (Including the Insectivores and Chiropterans) Mountain lion Bobcat Red fox Gray wolf Coyote Wolverine Marten River otter Mink Short-tailed weasel (ermine) Spotted skunk Striped skunk Black bear Grizzly bear Vagrant shrew Bats References Index x 31 34 36 39 42 44 48 51 53 57 58 59 60 64 67 72 75 79 80 85 87 89 92 95 97 101 103 105 108 110 112 117 119 121 123 125 Life Zones ELEVATION PRECIPITATION FEET DRY MOIST WET 14,000 ARCTIC-ALPINE ZONE[1] above timber-line; small, mat-like plants. 13,000 pika 12,000 mountain sheep 11,000 HUDSONIAN ZONE spruce red squirrel 10,000 fir marten 9,000 CANADIAN ZONE quaking aspen beaver Douglas fir, mule deer 8,000 TRANSITION ZONE tassel-eared squirrel 7,000 ponderosa pine, mountain lion 6,000 UPPER SONORAN ZONE[2] pinyon pine deer mouse 5,000 juniper bobcat sagebrush pronghorn 4,000 LOWER SONORAN ZONE[3] 3,000 mesquite, kangaroo rat 2,000 giant cactus 1,000 kit fox HOT WARM COLD TEMPERATURE Notes [1]THIS BOOKLET DESCRIBES MAMMALS OF THE SOUTHWEST WHICH LIVE IN THE LIFE ZONES ABOVE THE LOW DESERT. SEE FLOWERS OF THE SOUTHWEST MOUNTAINS FOR PLANTS OF THESE ZONES. [2]SEE FLOWERS OF THE SOUTHWEST MESAS FOR PLANTS OF THIS ZONE. [3]SEE MAMMALS OF THE SOUTHWEST DESERTS FOR MAMMALS OF THESE ZONES. xii xi SEE FLOWERS OF THE SOUTHWEST DESERTS FOR PLANTS OF THIS ZONE. INTRODUCTION Geographic Limitations The only point in the United States at which four states adjoin is where Utah, Colorado, Arizona, and New Mexico come together. With adjacent portions of California, Nevada, and Texas, they contain all of our Southwestern Desert. Arizona and New Mexico especially, are known as desert States and for the most part deserve that appellation. Scattered over this desert country as though carelessly strewn by some giant hand are some of the highest and most beautiful mountains in our Nation. They may occur as isolated peaks magnificent in their loneliness, or as short ranges that continue but a little way before sinking to the level of the desert. On the other hand it is in Colorado that the Rocky Mountains reach their greatest height before merging with the high country in New Mexico, and all of the States mentioned have at least one range of major size. Two great highways cross this area from East to West. U.S. 66, “Mainstreet of America,” goes by way of Albuquerque and Flagstaff to Los Angeles; farther north U.S. 50 winds through the mountains from Pueblo to Salt Lake City and terminates at San Francisco. Significantly, they meet at St. Louis on their eastward course, and here for the moment we digress from geography to history. Westward Ho St. Louis in 1800 was a brawling frontier town. Strategically located at the point where the Missouri River meets the Mississippi, it was the jumping off place for those hardy souls adventurous enough to forsake the comforts of civilization for the unknown perils of the West. Already St. Louis was one of the fur centers of the world. Fashions of the day decreed that top hats be worn by men. The finest hats were made of beaver fur and no self-respecting dandy could be content with less. Trapping parties ascended the Missouri River as far as the mountains of Montana in search of pelts with which to supply the demand. When the animals became scarce in more accessible areas, trappers turned their attention to the mountains of New Mexico and Colorado. Hardships of the overland route, coupled with danger of attack by hostile Indians, discouraged all but the most hardy of a rugged breed. These “Mountain Men” as they became known, traveled in small parties with all the stealth and cunning of the Indians themselves. Gaunt from weeks of travel across the plains, they could rest in the Spanish settlement of Santa Fe for a few days before vanishing into the mountains. On the return trip they might again visit the Spanish pueblo or, eager for the night life of St. Louis, strike directly eastward across the prairies. Today’s highways, while not following their trails directly, certainly parallel them to a great degree. Little is known today of these early adventurers. A few written accounts have been printed, meager records of their catches have been noted, and here and there crude initials and dates carved on isolated canyon walls attest their passing. Their conquest of the West has faded into oblivion but it must be regarded as the opening wedge of American progress into the Southwest. Mountains as Wildlife Reservoirs Today’s traveler spans in hours distances across these same routes that took weary weeks of heartbreaking toil a century ago. As he rides in cushioned ease he seldom pauses to reflect on the changes that have taken place since those early days. The great herds of bison with their attendant packs of wolves have vanished and in their place white-faced cattle graze on the level prairies. In the foothills the pronghorns have taken their last stand. Cities have sprung up on the camping sites of nomadic tribes that roamed the whole area between the Mississippi River and the Rocky Mountains. Only the mountains seem the same. In winter these massive ranges form a barrier against the storms that sweep in from the northwest. More important—these great storehouses of our natural resources that in early days meant only gold and furs, and perhaps sudden death to the pioneers, have now been unlocked by their descendants. The glitter of gold and the glamour of furs pales when contrasted with the untold values that have since been taken out in the baser metals and lumber. This phase too is now coming to an end. It is becoming evident that in the face of our ever increasing population these natural playgrounds are destined to become a buffer against the tensions that we, as one of the most highly civilized peoples of the world, undergo in our daily life. Within another century they will represent one of the few remaining opportunities for many millions of Americans to get close to nature. As such the proper development and preservation of mountainous areas and their values is of vital importance to our Nation. Mountains of the Southwestern States have been formed by three major agencies. These are, in order of importance, shrinkage of the earth’s interior to form wrinkles on the surface; faulting, with subsequent erosion of exposed surfaces; and volcanic action. The first method is responsible for most of the large ranges, such as the coastal mountains of California and the Rocky Mountains. Faulting is responsible for many of the high plateau areas where one side may be a high rim or cliff and the other a gently sloping incline. The Mogollon Rim, extending across a part of Arizona and into New Mexico, is a classic example in this category. Volcanic action may result in great masses of igneous rock being extruded through cracks in the earth’s surface or it may take the form of violent outbursts in one comparatively small area. Several mountain regions in Arizona and New Mexico are covered with huge fields of extruded lava. Capulin Mountain in New Mexico is an example of a recent volcano which built up an almost perfect cone of cinders and lava. Less noticeable than the mountains, but important nevertheless, are the tablelands of the Southwest. These mesas, too high to be typical of the desert, and in most cases too xiv xv xiii low to be considered as mountains, partake of the characteristics of both. Desert “Islands” The mountains of the Southwest have been compared to islands rising above the surface of a sea of desert. This is an apt comparison for not only do they differ materially from the hot, low desert in climate, but also in flora and fauna. Few species of either plants or animals living at these higher altitudes could survive conditions on the desert floor with any more success than land animals could take to the open sea. Their death from heat and aridity would only be more prolonged than that by drowning. Thus certain species isolated on mountain peaks are often as restricted in range as though they actually were surrounded by water. At times this results in such striking adaptation to local conditions that some common species become hardly recognizable. This is the exception to the rule however; most of the animals in this book are either of the same species as those in the Northern States or so closely allied that to the casual observer they will seem the same. Conditions that enable these species ordinarily associated with the snowy plains of the Midwest and the conifer forests of the North to live in the hot Southwest are brought about either directly or indirectly by altitude. Life Zones There are in this nucleus of four States a total of six life zones, (See map on page x.) The two lowest, the Lower and Upper Sonoran Life Zones, range from sea level to a maximum elevation of about 7000 feet. These two have been covered in the book “Mammals of the Southwest Deserts.” The remaining four—Transition, Canadian, Hudsonian, and Alpine Life Zones—will furnish the material for this book. The names of these zones are self explanatory, because they are descriptive of those regions whose climates they approximate. Unlike the two life zones of the desert, which merge almost imperceptibly together, these upper zones are more sharply defined. They may often be identified at a great distance by their distinctive plant growth. It should be noted that plant species are even more susceptible to environmental factors than animals and are restricted to well defined areas within the extremes of temperature and moisture best suited to their individual needs. Thus each life zone has its typical plant species, and since animals in turn are dependent on certain plants for food or cover, one can often predict many of the species to be found in an individual area. The Transition Life Zone in the Southwest usually lies at an altitude of between 7000 and 8000 feet. It encompasses the change from low trees and shrubs of the open desert to dense forest of the higher elevations. It is characterized by open forests of ponderosa pine usually intermingled with scattered thickets of Gambel oak. These trees are of a brighter green than the desert growth but do not compare with the deeper color of the firs that grow at a higher elevation. The Canadian Life Zone begins at an altitude of about 8000 feet and extends to approximately 9500 feet. The Douglas-fir must be considered the outstanding species in this zone although the brilliant autumn color of quaking aspens provides more spectacular identification of this area during the fall. Through the winter months when this tree has shed its leaves, the groves show up as gray patches among the dark green firs. At this elevation there is considerable snow during winter and correspondingly heavy rainfall in summer months. Under these favorable conditions there is usually a colorful display of wildflowers late in the spring. The Hudsonian Life Zone is marked by a noticeable decrease in numbers of plant species. At this altitude, (9500 to 11,500 feet), the winters are severe and summers of short duration. This is the zone of white fir which grows tall and slim so to better shed its seasonal burden of snow and sleet. In the more sheltered places spruce finds a habitat suited to its needs. Near the upper edge of the Hudsonian Life Zone the trees become stunted and misshapen and finally disappear entirely. This is timberline; the beginning of the Alpine Life Zone, or as it often called, the Arctic-Alpine Life Zone. Here is a world of barren rock and biting cold. At 12,000 feet and above the eternal snows lie deep on the peaks. Yet, even though at first glance there seems to be little evidence of life of any kind, a close scrutiny will reveal low mat-like plants growing among the exposed rocks and tiny paths leading to burrows in the rock slides. Among the larger mammals there are few other than the mountain sheep that can endure the rigors of this inhospitable region. These are the zones of the Southwest uplands. Altitudes given are approximate and apply to such mountain ranges as the San Francisco Peaks of Arizona and the Sangre de Cristo Mountains in New Mexico. As one travels farther north the zones descend ever lower until in the Far North the Arctic-Alpine Life Zone is found at sea level. Since climate more than any other factor, determines the types of plants and animals that can live in a given area it is only natural that on these mountain islands many species entirely foreign to the surrounding deserts are found at home. Though it would seem that because of the relative abundance of water at higher elevations the upland species would have the better environment, this is not entirely true. Balanced against this advantage are the severe winters which, in addition to freezing temperatures, usher in a period of deep snows and famine. Even though many species show a high degree of adaptation to these conditions, an especially long or cold winter season will result in the death of weaker individuals. Man and Wilderness The effects of man’s presence on the upland species is perhaps not as serious as on those of the desert. Though he has been instrumental in upsetting the balance of nature everywhere, it has been chiefly through agriculture and grazing. Because of the rough broken character of much high country in the Southwest the first is impossible in many cases and the second only partially successful. There are other factors however which menace the future of the upland species. Among these are: hunting pressures, predator control, and lumbering. Even xvi 1 fire control, admirable as it may be for human purposes, disrupts the long cycles which are a normal part of plant and animal succession in forested areas. These are only a few of the means by which man deliberately or unconsciously decimates the animal population. They are set down as a reminder that unless conservation and science cooperate in management problems, it is conceivable that many of our common species could well become extinct within the next 100 years. Our natural resources are our heritage; let us not waste the substance of our trust. As our wilderness areas shrink it seems that our people are gradually becoming more interested, not only in the welfare of our native species but in their ways as well. This type of curiosity augurs well for the future of our remaining wild creatures. In times past an interest in mammals was limited mainly to sportsmen who often knew a great deal about where to find game animals and how to pursue them. Their interest usually ended with the shot that brought the quarry down. Today many people have discovered that a study of the habits of any animal in its native habitat is a fascinating out-of-doors hobby in a virtually untouched field. With patience and attention to details the layman will occasionally discover facts about the daily life of some common species that have escaped the attention of our foremost naturalists. This is no criticism of the scientific approach. It is recommended that for his own benefit the nature enthusiast learn a few of the fundamentals of zoology, particularly of classification and taxonomy, which mean the grouping and naming of species. Classification of Animals Classification of animals is easy to understand. Briefly, they are divided into large groups called orders. These are further divided into genera, and the genera in turn contain one or more species. Scientific names of animals are always given in Latin. Written in this universal language they are intelligible to all scientists, regardless of nationality. It is a mistake to shy away from them because they are cumbersome and unfamiliar to the eye. They usually reveal some important characteristic of the animal they stand for. This is their true function; it seems to this writer that it is a mistake to name an animal after a geographical location or a person, although it is frequently done. The literal translations of specific names in this book will illustrate this point. See how much more interesting and how much more easily remembered those names are which describe habits or physical attributes of the creature. Described herein are but a part of the species native to the Southwestern uplands. Those chosen were selected because they are either common, rare, or unusually interesting. Collectively they make up a representative cross section of the mammals that live above the deserts of the Southwest. For further information on these and other mammals of the region see the list of references on page 123. HOOFED ANIMALS Artiodactyla (even-toed hoofed animals) This order includes all of the hoofed animals native to the United States. These are the mammals which are ordinarily spoken of as the “cloven-hoofed animals.” An odd-toed group (Perissodactyla), which includes the so-called wild horses and burros, cannot properly be included as natives since these animals date back only to the time of the Spanish conquest of our Southwest. In earlier geologic ages horses ranged this continent, but in more primitive forms than those now found in other parts of the world. Through a study of fossil forms it has been determined that our present hoofed animals evolved from creatures which lived on the edges of the great tropical swamps that once covered large areas of our present land masses. They were long-legged and splay-footed, well adapted to an environment of deep mud and lush vegetation. As the waters gradually disappeared and the animals were forced to take to dry land, their strange feet underwent a slow transformation. Because they had become accustomed to walking on the tips of their toes to stay up out of the mud, the first toe did not touch solid ground at all in this new environment. Since it was of no use it soon vanished entirely or became vestigial. Some species developed a divided foot in which the second and third toes and the fourth and fifth toes combined respectively to bear the animal’s weight. Eventually the third and fourth toes assumed this responsibility alone, and the second and fifth toes became dew claws. These are the cloven-hoofed animals of today. In other species the third toe was developed to bear the weight, and this resulted in a single-toed group of which the horse is an example. In all cases an enormous modification of the nails or claws with which most animals are equipped has resulted in that protective covering called the hoof. The under surface of the foot is somewhat softer and corresponds to the heavy pad that protects the bottom of a dog’s toe. This brief explanation refers only in the broadest sense to the order as represented in the United States. The feet of the various species have become so specialized to their separate ways of life that an individual can usually be easily identified by its tracks alone. It is quite possible that many species are still undergoing subtle changes in this respect. With but one exception the cloven-hoofed animals of our southwestern mountains bear either horns or antlers. The exception is the collared peccary, “javelina,” (pecari tajacu) which, during the heat of the summer, sometimes ascends to the Transition Life Zone in southern Arizona and southwestern New Mexico. Essentially an animal of the low desert, it will not be included in this book. The species which have hollow, permanent horns are the bighorn and pronghorn. The pronghorn is distinctive in shedding the sheaths of its horns each year, but the hollow, bony core remains intact. In this group both sexes bear horns. Animals bearing antlers are the elk and the deer. The 2 3 antlers are deciduous, being shed each year at about the same time as the winter coat. Only the males of these species have antlers, any female with antlers can be considered abnormal. The Southwest is fortunate in still having a number of the species of this order native to the United States. The bison can hardly be considered a wild species, since it exists now only through the efforts of a few conservationists who brought it back from virtual extinction. Mountain goats, caribou, and moose are the only other species not known to inhabit the Southwest. In Nature’s balance the order Artiodactyla seems to have been meant as food for the large predators. Their protection against the flesh eaters consists mainly in fleetness of foot, keen hearing, and a wide range of vision, as evidenced by the large eyes set in the sides of the head. They are but poorly equipped to actively resist attack by the larger carnivores. Their best defense is flight. Bighorn (mountain sheep) Ovis canadensis (Latin: a sheep from Canada) Range: This species, with its several varieties, inhabits most of the mountainous region of the western United States. In Mexico it occurs in the northern Sierra Madres and over almost the whole length of Baja California. Habitat map Habitat: Among or in the vicinity of more precipitous places in the mountains. Description: A blocky animal, rather large, with heavy, curving horns. Total length of adult male 5 feet. Tail about 5 inches. Weight up to 275 pounds. General color a dark gray to brown with lighter areas underneath belly and inside of legs. The rump patch is much lighter than any other part of the body; in most cases it can be described as white. Females are similar in appearance to the males except that they are smaller and the horns are much shorter and slimmer. Young, one or two, twins being common. Interesting as the desert varieties of this species may be in their adaptation to an environment that seems foreign to their nature, they cannot compare with the high mountain animal. Seen against the backdrop of a great gray cliff or silhouetted against the skyline of a snowy crest the bighorn has a magnificence that is thrilling. In flight it is even more spectacular as it bounds from one narrow shelf to another in an incredible show of surefootedness. Yet this airy grace is exhibited by a chunky animal that often weighs well over 200 pounds. The secret lies in the specially adapted hooves with bottoms that cling to smooth surfaces like crepe rubber and edges that cut into snow and ice or gain a purchase on the smallest projections of the rocks. The legs and body, though heavy, are well proportioned and so extremely well muscled that no matter what demands are placed on them this sheep seems to have a comfortable reserve of power. No doubt the display of complete coordination adds to the illusion of ease with which it ascends to the most inaccessible places. Descents often are even more spectacular, the animal seldom hesitating at vertical leaps of 15 feet or more down from one narrow ledge to another. 4 bighorn bighorn In the high mountains where this sheep prefers to make its home it usually ranges near or above timberline. During winter storms it may sometimes be forced down into the shelter of the forests, but as soon as conditions warrant it will go back to its world of barren rocks and snow. Here, with an unobstructed view, its keen eyes can pick out the stealthy movements of the mountain lion, the only mammal predator capable of making any serious inroads on its numbers. It has few other natural enemies. A golden eagle occasionally may strike a lamb and knock it from a ledge, or a high ranging bobcat or lynx may be lucky enough to snatch a very young one away from its mother, but these are rare occurrences. Bighorns depend mainly on browse for food. This is only natural since in the high altitudes they frequent little grass can be found. Usually there is some abundance of low shrubs growing in crevices on the rocks, however, and many of the tiny annuals are also searched out during the short summer season. At times a sheltered cove on the south exposure of a mountain will become filled with such shrubs as the snowberry, and the sheep take full advantage of such situations. As a rule they keep well fed for, scanty though it seems, there are few competitors for the food supply above timberline. I have observed these sheep many times in the Rockies. Perhaps my most memorable experience with this species was on Mount Cochran in southern Montana. It was a gray, blustery day in September with occasional snow flurries sweeping about the summits. On the eastern exposure of the mountain a steep slope of slide rock extended for perhaps 1,000 feet from one of the upper ridges to timberline. Not expecting to see any game at that elevation, I made my way up this slope with no effort to keep quiet. In my progress several rocks were dislodged and went rattling down across the mass of talus. At the summit of the ridge a low escarpment made a convenient windbreak against the gale that was tearing the clouds to shreds as they came drifting up the opposite slope, and I sat down to catch my breath before entering its full force. As I sat there surveying the scene spread out below, my attention was attracted by a low cough close by. Looking to the left about 40 feet away and 15 feet above me, I saw two magnificent rams standing on a projecting point looking down at me. They seemed to have no fear; rather they evinced a deep curiosity as to what strange animal this was that had wandered into their domain. For the better part of a half hour I hardly dared breathe for fear of frightening them. At first they gazed at me fixedly, occasionally giving a low snorting cough and stamping their feet. Then as I did not move, they would wheel about and change positions, sometimes taking a long look over the mountains before bringing their attention back. Finally when the cold had penetrated to my very bones, I stood up. They were away in a flash, reappearing from behind their vantage point with two ewes and an almost full-grown lamb following them. While I watched they dashed at a sheer cliff that reared up to the summit, and with hardly slackening speed bounded up its face until they were lost in the clouds. Although this happened in 1928 the experience is as vivid in my mind as though it happened yesterday. Perhaps the most striking feature of bighorns seen at this close range is the eyes. They might be described as a clear, golden amber with a long oval, velvety black pupil. Credited with telescopic vision, they must be some of the most useful as well as beautiful eyes to be found in the animal kingdom. Pronghorn (antelope) Antilocapra americana (Latin: antelope and goat, American) Range: West Texas, eastern Colorado and central Wyoming to southern California and western Nevada, and from southern 5 6 Saskatchewan south into northern Mexico. Habitat map Habitat: Grasslands of mesas and prairies, mostly in the Upper Sonoran Zone. Description: A white and tan colored animal, considerably smaller than a deer; horns with a single flat prong curving forward. Total length about 4 feet. Tail about 6 inches. Average weight 100 to 125 pounds. Color, tan or black shading to white under belly and insides of legs. Two conspicuous white bands under the neck, and the large white rump patch of erectile hairs are unlike the markings of any other native animal. A short, stiff mane of dark hairs follows the back of the neck from ears to shoulders. Hooves black, horns also black except for the light tips on those of older males. Both sexes horned. Young, usually two, born in May. pronghorn pronghorn Pronghorns are unique among cloven-hoofed animals of the Southwest. There is only one species, with several subspecies; a variety 7 8 mexicana, once common along the Mexican border, is considered extinct in this country. The pronghorn has no “dew claws” like most other animals with divided hooves. It has permanent bony cores in its horns but sheds the outer sheaths each year. When these drop off the succeeding sheaths are already well developed. Although at first these new sheaths are soft and covered with a scanty growth of short stiff hairs, corresponding to the velvet in antlered animals, it does not take long for them to harden and become dangerous weapons. They reach full development at about the time of the rut; bucks have been known to fight to the death in the savage encounters that break out at this time. Were it not for its unusual horns the pronghorn probably would be known by a common name such as the white-tailed antelope, for the beautiful white rump patch is undoubtedly its next most conspicuous feature. However, at least two other animals have been named “antelope” because their posteriors have some similarity. They are the white-tailed ground squirrel and the antelope jackrabbit of the Sonoran Life Zone. The ground squirrel (Citellus leucurus) has merely a white ventral surface on its tail which may or may not act as a flashing signal when flipped about, but the antelope jackrabbit (Lepus alleni) has a rump patch that bears a striking likeness to the pronghorn’s both in appearance and manner of use. In both cases the rump patches are composed of long, erectile white hairs which are raised when the animal is alarmed. In flight they are thought to act as warning signals; at any rate they are very effective in catching the eye, and on the open plains the pronghorn’s can be seen at a distance where the rest of the animal is indistinguishable. It may well be, on the other hand, that this flashy ornament is meant to attract the attention of an enemy and lead it in pursuit of an adult individual rather than allowing it to discover the helpless young. Neither animal can be matched in speed on level ground by any native four-footed predator. In times past the pronghorn usually lived in the valley and prairie country. In the Southwest it roamed over much of both the Upper and Lower Sonoran Life Zones, wherever suitable grass and herbage could be found. On the prairies of the Midwest bands of pronghorns grazed in close proximity to herds of buffalo. During the middle of the last century it was the only animal whose numbers even approached those of the latter. More adaptable than the buffalo, it has retreated before the advance of civilization and taken up new ranges in rough and broken country which is unsuited to agriculture. As a rule this is much higher than its former range. Pronghorns are no longer found in the Lower Sonoran Life Zone, except as small bands that have been introduced from farther north. The greatest population now ranges in the upper portions of the Upper Sonoran and along the lower fringe of the Transition Life Zone. The animal has always been considered migratory to some extent because it moved from mesa summer ranges to the protection of warmer valleys during winter months. This habit is even more pronounced in later years at the higher levels it now inhabits. These slim, long-legged creatures are virtually helpless in deep snow and avoid it whenever possible. They have even been known to mingle with cattle and join with them at the feed racks during severe winters, an indication of the extreme need to which shy pronghorns are sometimes reduced. They are essentially grazing animals. In the past they ate prairie grasses during the summer; in winter these same grasses made excellent hay that lost little in nourishment from having dried on the roots. In addition, they ate low herbage and nibbled leaves, buds, and fruits from shrubs that grew along the watercourses. Their food today is much the same except that in the many areas where they receive competition from range cattle they undoubtedly resort to more browse than formerly. Natural enemies of the pronghorn are legion, their success indifferent. Every large carnivore will snap at the chance to take one, and even the golden eagle has been known to kill them. The most serious depredations are carried out on those young too small to follow the mother. However, these attacks are fraught with danger, for the females are very courageous in the defense of their young and at times several will join in routing an enemy. In addition to this protection accorded them by adult members of the band, the young have an almost perfect camouflage in their plain coats that blend so closely with the color of the grass in which they usually lie concealed. Because of their fleetness, few adults fall prey to predators. Many attempts have been made to clock the speed of the pronghorn in full flight but the estimates vary greatly. Although a fast horse can keep up with one on smooth, level ground, it is soon outdistanced on stony soil or in rough country. baby pronghorn baby pronghorn Bison (buffalo) Bison bison (Teutonic name given to this animal) Range: At present bison exist only in widely scattered sanctuaries. In Colonial times they ranged from southern Alaska to the Texas plains, from the Rocky Mountains to the Atlantic, and as far south as Georgia. They are known in historic times in Utah, Colorado, and New 9 Mexico. Habitat map Habitat: Mainly grasslands; a comparatively small number known locally as “wood” bison lived in the fringes of the forests. Description: Although bison are familiar to almost everyone, some figures on weights and dimensions may be surprising. Bulls weigh up to 1800 lbs., reach 6 feet height at the shoulders and up to 11 feet in length, of which about 2 feet is the short tail. Cows average much smaller from 800 to 1000 pounds, and rarely over 7 feet long. Both sexes have heavy, black, sharply curving horns, tapering quickly to a point, and a heavy growth of woolly hair covering most of the head and forequarters. A large hump lies over the latter and descends sharply to the neck. The head is massive, horns widely spaced, and small eyes set far apart. A heavy “goatee” swings from the lower jaw. All these features combine to give the animal a most ponderous appearance. Nevertheless, bison are surprisingly agile and are not creatures with which to trifle, especially in the breeding season, when bulls will charge with little provocation. Like most wild cattle, bison normally bear but one calf per year. Twins are uncommon. The history of the bison is unique in the annals of American mammalogy. It hinges on simple economics, reflecting transfer of the western prairies from Indian control to white. It is a pitifully short history in its final stages, requiring only 50 years to drive a massive species, numbering in the millions, from a well balanced existence to near extinction. Yet considering the nature of civilization and progress there could have been no other end, so perhaps it is well that it was quickly over. For countless centuries the bison had roamed the prairies, their seasonal migrations making eddies in the great herds that darkened the plains. They were host to the Indian, and to the gray wolf, yet so well were they adapted to their life that these depredations were merely normal inroads on their numbers. They drifted with the seasons and the weather cycles, grazing on the nutritious grasses of the prairie. Weather and food supply; these were the main factors which controlled the “buffalo” population until the coming of the white man. The first white man to see an American bison is thought to have been Cortez, who in 1521 wrote of such an animal in Montezuma’s collection of animals. This menagerie was kept in the Aztec capitol on the site of what is now Mexico City. There the bison was an exotic, hundreds of miles south of its range. In 1540 Coronado found the Zuni Indians in northern New Mexico using bison hides, and a short distance northeast of that point encountered the species on the great plains. The eastern edge of the Rio Grande Valley in New Mexico seems to have been the western limit of bison in the Southwest. Unfavorable climate, plus the comparatively heavy Indian population of the valley probably combined to halt farther penetration in that direction. From 1540 until 1840 the white man limited his activities on the western plains to exploring. American colonization had reached the Mississippi River, but remained there while gathering its forces for the expansion which later settled the West. Under Mexican rule, the Southwest progressed very slowly. Then in the span of 50 years a chain of events occurred which determined the destiny of the West and sealed the fate of the bison herd. 10 bison bison Outstanding among these events were: the War with Mexico, 1844; the 1849 Gold Rush to California; the Gadsden Purchase in 1854; and completion of the transcontinental railroad in 1868. The first three added new and important territory to the United States. This made construction of transportation and communication facilities a vital necessity, hence the railroad. Completion of the Union Pacific Railroad in 1868 divided the bison population into southern and northern herds and made market hunting profitable. Three factors contributed to extermination: profit in the traffic of hides, meat, and bones; control of troublesome Indian tribes through elimination of one of their major sources of food; and finally, removal of any competition on the grassy plains of Texas and Kansas against the great herds of Longhorn cattle which were beginning to make Western range history. In 1874, only 6 years after completion of the Union Pacific, the slaughter of the southern herd was complete. It is of interest to note that not one piece of legislation was passed to protect the southern herd. The northern herd did slightly better. Closed seasons were established in Idaho in 1864, in Wyoming in 1871, Montana in 1872, Nebraska in 1875, Colorado in 1877, New Mexico in 1880, North and South Dakota in 1883. Nevertheless, the herd dwindled, and by 1890 was nearly extinct. Since that time, through careful management, a few small herds have been established in Parks and refuges, but today the bison must be considered more a domesticated animal than a wild one. Although the animal was not as important economically to the southwestern as to the plains Indians, it was a religious symbol of some value. Archeological finds far west of the historic range, and dances still used in ceremonies, reveal that several southwestern tribes sent hunting parties eastward into bison country. This must have been very dangerous, for plains Indians would have considered them invaders. Bison were food, shelter, and clothing to them. Imagine their consternation when white men began to slaughter the source of their living. There are today but few reminders of the great herds of the west. Perhaps one well versed in the ways of these wild cattle could still find traces of the deeply cut trails which led to the watering places, or shallow depressions where the clumsy beasts once wallowed in the mud. Many of the Indian dances recall the importance of this animal to primitive man. Perhaps our most constant reminder is the coin which commemorates this symbol of the wild west, showing the Indian on one side and the bison on the other. Mule deer Odocoileus hemionus (Greek: odous, tooth and koilus, hollow. Greek: hemionus, mule) Range: Western half of North America from Central Canada to central Mexico. Habitat map 12 11 Habitat: Forests and brushy areas from near sea level to lower edge of the Alpine Life Zone. Description: A large-eared deer with a tail that is either all black above or black tipped. Total length of an average adult about 6 feet. Tail about 8 inches. The coat is reddish in summer and blue-gray in winter. Under parts and insides of legs lighter in color. Some forms of this species have a white rump patch, others none. The tail may be black-tipped, or black over the whole dorsal surface, but is more sparsely haired than that of other native deer and is naked over at least part of the under surface. Only the bucks have antlers. These are typical in forking equally from the main beam. They are shed every year. mule deer mule deer The mule deer is typical of the western mountains. Even in early days it was never found east of the Mississippi and now is seldom seen east of the Rockies. Only one species is recognized in the United States, although over its vast range are many subspecific forms. All are notable for the size of their ears, from which derives the common name “mule.” The black-tailed deer of the Pacific Coast, long considered a distinct species, is now rated a subspecies of the mule deer. In a general way the deer of the United States may be divided into two groups, these separated geographically by the Continental Divide. East of this line is the territory occupied by the white-tailed group; westward of it live the mule deer. Inasmuch as species seldom stop abruptly at geographical lines, we find in this instance that a whitetail subspecies, locally known as the Sonora fantail, is found along the Mexican border as far west as the Colorado River, territory also occupied by desert-dwelling mule deer. In like fashion the mule deer of the Rocky Mountains can even now be seen in the Badlands of North Dakota, several hundred miles east of the Continental Divide and well within the western range of the plains white-tailed. Though the two species mingle in places, they are easily distinguished from each other, even by the novice. Because in many cases the animal is seen only in flight, the manner of running is perhaps the most prominent field difference. The mule deer, adapted to living in rough country, bounds away in stiff-legged jumps that look rather awkward on the level but can carry it up a steep incline with surprising speed. The white-tailed, on the other hand, stretches out and runs at a bobbing gallop. Deer seldom take leisurely flight from a human, usually straining every muscle to leave their enemy as soon as possible. In the rough, broken country frequented by mule deer this tactic often makes considerable commotion. I am reminded of a herd of an estimated 70 deer that I jumped on a steep mountainside in southern Utah. The crashing of brush, crackling of hooves, and noise of rocks kicked loose in their flight created the impression of a landslide. Another easily seen field difference between mule and white-tailed deer is the dark, short-haired tail of the former as compared with the great white fan of the latter. The tail of the mule deer seems in no way to be used as a signal. In flight it is not wagged from side to side as is