AMPHIBIANS AND REPTILES

- 0F | GRAND CANYON • NATIONAL PARK

Natural History Bulletin No. 9

Grand Canyon Natural History Association

July, 1938 GRAND CANYON NATURAL HISTORY ASSOCIATION ADVISORY COUNCIL

Educational Development: Dr. John C. Merriam, President, Carnegie Institution. Dr. Harold S. Colton, Director Museum of Northern Arizona.

Geology: Mr. Francois 3. Katthes, U. S. Geological Survey.

Paleontology: Dr. Charles E. Resser, U. S. National Museum, Dr. Charles W. Gilmore, U. S. National Museum.

Mammalogy: Mr. Vernon Bailey, U. S. Biological Survey.

Ornithology: Mrs. Florence M. Bailey, Fellow, American Ornithologist's Union.

Herpetology: Mr. L. M. Klauber, San Diego Museum of Natural History.

Botany: Dr. Forrest Shreve, Desert Laboratory, Carnegie Institution.

Ethnology: Dr. Clark Wissler, American Museum of Natural History.

Archeology: Mr. Harold S. Gladwin, Gila Pueblo. Mr. Jesse L. Nusbaum, Superintendent, Mesa Verde National Park. AMPHIBIANS AND REPTILES OF GRAND CANYON NATIONAL PARK

NATURAL HISTORY ASSOCIATION BULLETIN NO. 9 July, 1938

National Park Service, Grand Canyon Natural Grand Canyon National Park History Association

This bulletin is published by the Grand Canyon Natural History Association as a pro­ ject in keeping with its policy to stimulate interest and to encourage soientific researoh and investigation in the fields of geology, botany, zoology, ethnology, aroheology and related subjects in the Grand Canyon region. This number is one of a series issued at irregular intervals throughout the year.

Notification of the publication of bul­ letins by the Association will be given, upon date of release, to such persons or institu­ tions as submit their names to the Executive Secretary for this purpose. The following bulletins are available at present:

No. 1 - Mammals of the Grand Canyon Region 25/ No. 2 - History and Exploration of the Grand Canyon Region...... 15/ No. 3 - Trees of Grand Canyon National Park 50/ No. 4 - Contributions to Grand Canyon Bird Study.• Lay No. 5 - Contributions to Grand Canyon Geology IB/ No. 6 - Check-list of Plants of Grand Canyon National Park 60/ No. 7 - Prehistoric Nan in the Southwest 25/ No. 8 - Check-list of Birds of Grand Canyon Nati onal Park 25/

M. R. Tillotson, Edwin D. MoKee Superintendent Exec. Sec'y. and Editor

This Bulletin - 25/ 1 AMPHIBIANS AND REPTILES OF GRAND CANYON NATIONAL PARK

By Hatt N. Dodge*

Introduction W HERE are those horrid snakes? I want to see them." This remark, frequently addressed to the keepers at a large metropolitan zoo, expresses the attitude of many persons toward snakes and, to a lesser degree, toward lizards, toads, salamanders and turtles. That certain creatures should seem repulsive, and at the same time exercise a strong appeal indi­ cates a peculiar contradiction in mankind's emotional makeup. Superstition, imagination and exaggeration have built up a mass of false information regarding these creatures. This has engendered an entirely groundless fear and hatred of these animals, especially snakes, and has brought about a widespread persecution resulting in considerable economic loss, particu­ larly to farmers. PARK REPTILES, IN GENERAL, ARE HARMLESS

HE Grand Canyon is favored with an interesting assort­ T ment of reptilian life which, with the exception of the rattlesnake, is entirely harmless to man. Rattlesnakes are very rare within the Park and, as far as the writer can ascer­ tain, not a single fatality from snakebite has taken place in the area since it was placed under the jurisdiction of the National Park Service in 1919.

* To Messrs. Klauber and Perkins of the San Diego Museum of Natural History, the writer expresses his gratitude for valuable assistance in giving detailed technical advise and constructive ori- ticism in the preparation of this paper. 2

GRAND CANYON OFFERS FERTILE FIELD

FOR REPTILE STUDY

ISITORS to Rational Parks are, in the main, interested V in the enjoyment of superlative scenery. But moun­ tains, lakes, glaciers and sunsets alone do not constitute scenery. Without the forests, the flower-filled fields, and the animals that inhabit them, these remaining vestiges of the onoe great American wilderness would be barren indeed. People are gradually learning that a richer, deeper enjoyment of these soenic areas may be derived through acquiring a basio knowledge of the magnificent manifestations of Kature repre­ sented there. In the Grand Canyon, climatic conditions have provided a great variety of habitats which enable the visitor to find concentrated here a wealth of plant and animal life. Reptiles are no exception to this rule and of fer a most inter­ esting field for study.

The casual visitor will find that a little knowledge about the reptiles that he may meet on road or trail will af­ ford many moments of pleasure. For the herpetologist, there remains in Grand Canyon much to be learned from a detailed study of reptilian life which will contribute to the meager knowledge now on hand. It is the purpose of this publication to offer the interested visitor in non-technical form an out­ line of the information now available on amphibians and rep­ tiles of this National Park, and at the same time provide the research student with a synopsis of the work already accompli­ shed as a basis for further study. The writer wishes it to be fully understood at the outset that he has done no scientifio work whatever in this field. He has merely attempted to ool- lect all information available on Park amphibians and reptiles and to present it in systematic, accurate, readable form.

PREHISTORIC AfiPHIBIAlB AND REPTILES

AT GRAND CANYON

RAHD CANYON affords access to a remarkably complete Q cross-section of rock layers representing the earth's early history. It holds in its walls an invaluable record of the processes by which the earth's crust was built and also of the plants and animals that inhabited this portion of our sphere during past ages. In several formations in its upper 5

walls and in certain Painted Desert horizans, (extensions of which are known to have overlaid the present surface rocks of Grand Canyon National Park) have been found footprints of land and water animals. Careful studies of these imprints indi­ cate that they were probably made by amphibians and reptiles some of which were similar to modern forms inhabiting the re­ gion today. The Grand Canyon, thus, not only aids the scien­ tist in determining the relative position occupied by amphi­ bians and reptiles in the development of life throughout the ages, but also stimulates his interest by offering for obser­ vation the evolutionary remnants of a form of animal life that at one time dominated the face of the earth.

AMPHIBIANS AND REPTILES

AMONG EARLIEST LAND ANIMALS

OOLOGISTS have presented a mass of evidence to show Z that land animals developed from water-inhabiting forms that, through innumerable generations, were able to divorce themselves gradually from a water environment. Since such a drastic change of habitat must have taken a great amount of time, it is logical to expect that many of the animals of in­ termediate generations lived both on land and in water. Am­ phibians of today possess the ability to do this, or, perhaps we should say, are restricted by it. The adults may live in moist locations on land but for the fundamental processes of reproduction, they must return to water where the young spend the first stages of the life cycle. The individual during his life thus follows the evolutionary program of his kind or, as Dr. Cockerell* aptly remarks, "climbs his family tree".

If we may accept the amphibian as the form of life link­ ing the land and water vertebrates, the reptiles may be consi­ dered as among the first types of purely land-inhabiting animals. This belief is borne out not only by geological evidence, but also by the close relationship of amphibians to reptiles as indicated by the fact that these are the only groups of land vertebrates which, in common with the fishes, are cold blooded. Obviously for a life in the water where temperature changes are comparatively slight, an ability to regulate the body temperature is not of vital importance.

* See references at end. 4

PRIMITIVE CHARACTERISTICS HAVE BEEN RETAINED NDER atmospheric conditions where temperature fluctua­ tions are great, inability to meet such changes is a seriouUs menace to life. It is interesting to note, however, that many forms of amphibians and reptiles, have been able to survive regardless of this handioap. They have merely been restricted to certain environments by it. Their vital pro­ cesses are slowed down as the thermometer drops and they are correspondingly aocelerated by a rise in temperature*. Thus all reptiles and amphibians require a fairly warm habitat to enable them to capture their food and they cannot survive in regions where low temperatures prevail. Many forms, however, have the ability to hibernate, or go into a state of dormancy, when they retire to protected spots, and thus they are able to pass through periods of cold weather. For this reason some amphibians and reptiles are numerous in temperate regions where the winters are not too long and with the coming of warm weather they reappear in large numbers. Amphibians which re­ turn to activity with the arrival of warm spring rains have given rise to the superstition, still widely believed, that they "came down with the rain". Another superstition that "horned toads" may remain dormant for years sealed in stone Cavities is entirely without foundation in fact.

ENVIRONMENTAL REQUIREMENTS DETERMINE DISTRIBUTION

HE limitations imposed upon reptiles and amphibians by their environmental requirements naturally have much to do Twith their distribution throughout the world and, in a sim­ ilar manner, throughout the Park. Adult amphibians require moist locations and must have at least semi-permanent pools of water for breeding, hence they are not found far from mois­ ture. The generally dry conditions prevailing throughout Grand Canyon National Park account for the lack of amphibians. The few pools, streams, "sinks", springs, seeps and other water souroes within the Park are, however, inhabited by seve­ ral species of this group. Reptiles, on the other hand, have

* This characteristic has been exploited by the wri­ ter in obtaining the majority of photographs used in this publication. After an hour of reposing in an icebox, reptiles are so sluggish for several minutes that they form excellent photographic subjects. 5

developed tough, scaly skins which enable them to resist arid oonditions, and the Canyon with its hot, dry, insect-infested slopes and its relatively short winter season provides ideal oonditions for these animals. They are widely distributed throughout the Park.

Although the Grand Canyon in general provides habitats favorable to reptilian life, some of the territory within the Park boundaries is not at all suited to the requirements of these creatures. Wide differences in climatic conditions within the relatively small area of the Park are due to the great elevation variations. From the Canyon bottom which is between 1,000 and 3,000 feet above sea level to the Kaibab Plateau near the northern b oundary where elevations exceed 9,000 feet, there is an altitudinal range of 6,500 feet. This in climatic variation is equal to a latitudinal range of ap­ proximately 2,000 miles. Thus, within the Park, may be found locations representing nearly all of the climatic belts from northern Mexico to southern Canada. The Park may, for conven­ ience sake, be divided into climatic belts, resulting from altitudinal and exposure differences, whioh correspond with the same zones of the northern hemisphere caused by latitudin­ al variation. Biologists have given names to these zones and they will be used throughout this publication in discussing distribution.

LIFE ZONE TERMS AID REPTILE STUDY

ROM the bottom of Grand Canyon to an altitude of about 4,000 feet, climatic conditions are similar to those encountereF d at sea level in northern Mexico. At these eleva­ tions are found plant and animal associations characteristic of the hot, desert climate, therefore the belt is known as the Lower Sonar an Life Zone. From about 4,000 to 7,000 feet in altitude, within the Canyon, conditions prevail which are char­ acteristic of central United States and are referred to as the Upper Sonoran Life Zone. Between 7,000 and 8,000 feet, they resemble those of northern United States and the belt is known as the Transition Life Zone. Throughout the still higher por­ tions of the Park, the environment is similar to that of sout­ hern Canada, so the term Canadian Life Zone has been applied.

It must be understood that the elevational limits of Life Zones are by no means hard and fast, but overlap and blend in­ to one another. Furthermore, local conditions of exposure, air drainage, the presence of streams, and other factors may pro- 6

duce climatic islands, and fingers of one zone may intrude deeply into elevations that would normally contain another. Hence, in reptile distribution and in life-zone determination, altitudinal variations can not arbitrarily be followed any more than can latitudinal bounds when horizontal distribution is considered. Broadly, the life zone theory is a great aid in grasping the essential facts of reptile distribution and the student of reptiles will find that the terminology may be applied to include a much wider distribution of these crea­ tures than this publication is designed to cover. For inst­ ance, representatives of genera limited to a certain life zone in Grand Canyon National Park may be expected, with some de­ gree of certainty, to be found under the same life zone condi­ tions in other parts of the country.

SOLE HEEPETOLOGICAL PROBLEMS OF GRAND CANYON NATIONAL PARK

OOLOGISTS who have made a careful study of Grand Canyon Z animals have unearthed considerable evidence indicating that this great gash in the earth lias acted as a barrier to the movement of many small animals. This barrier, it is be­ lieved, is not a physical one, but rather an environmental hurdle. As an example, a certain species of small animal gradually extending its range northward reaches the edge of the great abyss. As individuals enter the Canyon they en­ counter a warmer, dryer climate. They find a different life zone ~ one'^ which the plants upon which they are accustomed to feed do not grow. Although physically capable of climbing the cliffs or crossing the river, they find their surroundings most unattractive, and return to the rim where conditions favorable to their life habits exist. Thus the extension of their range in a northerly direction is stopped.

Conversely, Grand Canyon may act, zoologists believe, as an avenue of travel, animals of the Lower Sonoran deserts to the south finding within it suitable conditions and gradually working their way along its course. If the barrier theory is correot, we may expect to find in the bottom of the Grand Can­ yon animals characteristic of the deserts of southern Arizona and northern Mexico, whereas on the North Rim we should find types characteristic of the regions to the north. There re­ mains in Grand Canyon National Park a most interesting problem in regard to reptile distribution in relation to this barrier theory. Very little has been done toward the solution of it. 7

For a detailed discussion of the problem see: Chas. M. Bogert, Herpetological Problems of Grand Canyon National Park, Grand Canyon Nature Notes, Vol. 7, Ho. 6, pps. 61-65, Sept. 19S2.

With the foregoing as an introduction, the remainder of this publication is devoted to a discussion of the various forms of amphibian and reptilian life that have been identi­ fied within the boundaries of Grand Canyon National Park. 8

Amphibians

ECHNICALLY, the term amphibian refers to all of the backboned animals whioh spend a portion of their life- cyclTe in water and the remainder breathing air. They literal­ ly lead a double life. In this group are included the newts, salamanders, toads, and frogs. Salamanders and newts are popularly called water-dogs, or mud-puppies. Sometimes, also, they are incorrectly referred to as lizards. The young of amphibians are found in quiet pools of water where the eggs have previously been deposited in gelatinous masses of strings by the females. Pollywogs and tadpoles are the popular names for the young. Adults customarily inhabit oool, moist, and shaded or dark locations. They are characterized by four legs and a moist skin whioh in some forms is lubricated by a thin layer of mucous or "slime". In general, the food of amphibians consists of insects. Because of this food preferenoe, frogs and toads are made welcome by gardeners and greenhouse men.

On aooount of their moisture requirements, the distribu­ tion of amphibians is limited to the vicinity of permanent or semi-permanent water sources. In Grand Canyon National Park suoh locations are few. Aside from the Colorado River whioh oooupies the Canyon bottom, roughly biseoting the Park from southeast to northwest, only five permanent streams worthy of the name are present. Springs and seeps occur infrequently, some being attended by small pools and short rivulets. On the Kaibab Plateau, a portion of which is inoluded in the North Rim area of the Park, heavier preoipitation and lower temperatures encourage the formation of springs and seeps while "sinks" are not unoommon. These bowl-shaped or funnel-like depressions are from five to twenty-five feet in depth and as muoh as 100 feet in diameter. Where the outlet at the bottom beoomes plugged, water from rain and melting snow accumulates to form a more or less permanent pool. Suoh sinks (and the man-made "tanks" formed by damming of gulleys) constitute the oenters of amphi­ bian activity on the plateau lands within the Park.

It is readily understandable from what has just been said that Grand Canyon National Park is not a fertile field for the study of amphibians. So few species are present that there is little difficulty in identifying the adult forms.

For this publication, descriptions and ranges of amphi­ bians should be oredited to Wright, A. A. and A. H.j Handbook 9

of Frogs and Toads, Comstock Publishing Co., Ithaca, New York, 1933, Illustrations are by the writer unless otherwise indi­ cated. Names and ranges are from Stejneger and Barbour; Cheok List of North American Amphibians and Reptiles, 3rd ed. 1933, Harvard Univ. Press.

Tiger Salamander

Ambystoma tigrinum (Green) (Also known as Water Dog, Mud Puppy, Mud Dog)

Description; This salamander is the only tailed amphibian of the park. St out-bodied, about five or six inohes in length, it is a glossy dark brown in color usu­ ally with many ir­ regular yellowish blotches sometimes arranged in cross bands. There is no longitudinal strip­ ing. The young are conspicuous by the Tt'yar Salorriondtr feathery external gilis, s omet imes carried into the age of reproduction.

Food and Habits; Largely insectivorous, this animal in­ habits quiet pools where it breeds. Adults are occasionally found beneath logs or stones in moist places some distance from permanent water sources.

Range; The Tiger Salamander is widely distributed over almost all of the United States, east of the Cascade Range and the Sierra Nevada, and extending southward over the northern portion of the Mexican Plateau.

Distribution Within the Park; Larvae of the Tiger Sala­ mander are common in tanks and pools on both rims* Few adults have been collected although several are recorded from each side of the Canyon. Distribution is general in the Upper Son- oran and Transition Life Zones.

Features of Interest: The young are popularly known as 10

Axolotl. According to Gadow, this name is derived from the Aztec meaning "Play-in-the-water". Coc- kerell believes the term may come from the Spanish, "Aqualote" or water lizard. Tiger Salamanders may be kept in captivity where they thrive on a meat diet.

Mud Puppies (larvae of Sa/a/rtonder)

Western Spadefoot Toad

Scaphiopus hammondil Baird (Also Hammond's Spea, Cope's Spea, and Hew Mexico Spea)

Description: Chubby and stout-bodied, the Spadefoot toad ranges from one and one-half to two and two-fifths inches in length. Its eyes, which are large and protuberant, have ver­ tical pupils, this feature serving to identify the Spadefoot. The skin is fine, relatively smooth, and dotted with small, roundish tubercles. The back is greenish with sides yellowish gray. Green spots are noticeable on the back, top of head, and legs. Forward parts are white with throat buffy and rear underpants purplish. The feet have extensive, fleshy webs.

Food and Habits: Adults are largely insectivorous, spending much of their time underground in burrows which they dig by backing into the soft, moist earth and scooping out the soil with the black, bony spades of their hind feet. They are rarely observed ex­ cept during the breeding season from mid April to Aug­ ust when they may be found IVesrorn Spadefoaf load about temporary rain pools or NOTE verf/cotcue pup if overflows. The eggs are laid 11

in cylindrical masses usually attached to plant stems, and hatch in a day and a half, or two days. The greenish-black tadpoles grow to large size. They are round-bodied with eyes close together and with a short tail. The musculature of the tail stands out prominently. The tadpole stage is from 30 to 40 days duration; the adults appear from May 20 to September 1. The tadpoles consume the larvae of insects, especially mos- quitos, and they are cannibalistic.

Range: Western and southwestern states,from Montana south to Texas and Mexico and westward to the Pacific coast and nor­ thern Lower California,constitute the range of the Spadefoot.

Distribution 'Within the Park: Little is known regarding the Spadefoot in Grand Canyon National Park. The adult3 are rather secretive in habit and are rarely seen. During the summer of 1937, the writer collected three adults at night following rains. One was just within the north boundary of the park and the others were about three miles north of Bright Angel Point on the highway. Larvae are extremely abundant in Greenland Lake on the North Rim in late June and early July.

Features of Interest: The call of the Spadefoot has been variously described and is a bubbling note. The males give voice to this cry while floating on the surfaoe of the water.

Spotted Toad Bufo punctatus Baird and Girard (Also Red-spotted Toad, Canyon Toad, and fielding's Toad)

Description: The delicately form­ ed, alert Spotted Toad is from two to three inches in length with a flattened body and broad back,evenly covered with tubercles or warts of small size. The body color varies from grayish green and tan to a drab reddish brown. Tub­ ercles on the baok, sides and legs may be reddish to orange oinnamon, and red or yellow tipped. Underparts of the hind legs are grayish. The head is broad between the eye6, the nostrils present a boxed appearance, and the eyelids appear pebbly. The call'is a 12

bird-like trill which may attain great volume and originates in the large sack of the male which forms a pouch beneath the chin and throat. This species may be confused with either the Desert Tree Toad or the Spadefoot at first sight, but the absence of discs on the toes differentiate it from the former, while the vertical-pupiled eyes of the latter afford an easy means of identification.

Food and Habits: This species is largely insectiverous. It breeds in rookbottomed pools and intermittent streams of desert canyon bottoms from April to July. The eggs, which are deposited singly and surrounded by a sticky gelatinous sub­ stance, hatch within three days. The tadpoles, which reach a length of one inch. are blaok with a whit­ ish tail having many evenly-spaced blaok dots. The larval period is from 40 to 60 days. Adults re­ main in moist crevices during dry weather and come out in rains.

Range: Western Texas, Arizona, Utah, Colorado, southern (left) Spotted Tood California, and Lower (fttoht) Desert- Tree Tooct ~ California. Distribution Within the Park: Probably the commonest amphibian in the park, the Spotted Toad is often seen about pools and streams within the Canyon. It has been observed mating and egg-laying at Indian Gardens in the latter part of July. In April, 19S7, the writer found many individuals en­ gaged in mating activities about Phantom Ranch, the males fill­ ing the night with their trilling cries. Tadpoles, probably of this species, were observed in Pipe Creek, in October. This species is very oommon along Bright Angel Creek, and is identi­ fied with the Lower Sonoran Life Zone.

Features of Interest: In their handbook, "Frogs and Toads", the Wrights report; "At Indian Gardens on the Bright Angel Trail on August 2, 1917, we found in a flat shallow area in water about six inches deep with plenty of algae on a muddy bottom, two egg complements of B. punetatus. Later, we found IS

no end of egg complements in all stages and took three or four transformed stages of B. punctatus here," From beneath rooks and within crevices the voices of these creatures issue in dry weather, and following rains the animals hop forth in numbers leading to the statement that they "came down with the rain".

Rocky Mountain Toad Bufo woodhousii Girard (Also VYoodhouse's Toad and American Toad)

Description: A large toad, two and three-fourths inches in length, this species greatly resembles the eastern Bufo amerioanus. but is lar­ ger. The back is grayish drab with a narrow light stripe down the middle. The sides are marked with several black 3pots. Underparts are a dark cream oolor. Tubercles and tips of toes are reddish brown. It is not likely to be confused with any other toad of the park.

Range: From Montana to Texas and west to southeastern California, this species is an inhabitant of the Great Basin and Great Plains regions.

Distribution Within the Park: The Rocky Mountain Toad has been recorded only twice within the park. It was reported from the lower reaches of Bright Angel Creek in June, 1935, by T. H. Eaton, Jr., and collected at Phantom Ranch in May, 1937, by Victor Veatch.

Features of Interest: Apparently at home in many environments, this species may be found where sufficient moisture prevails, altho­ ugh it is most abundant under Lower Sonoran and Upper Sonoran conditions. The vocal sac is a rounded throat and pouch noti­ ceably black in the males, and the call is a vibrating note of high pitch, sweet and musical. In captivity a peeping, queru­ lous note something like the oall of a baby chick is noted. 14

Desert Tree Toad

Hyla arenicolor Cope (Also Canyon Tree-toad, Canyon Tree Frog, Arizona Tree Frog, Sonoran Tree Frog)

Description: Yfiien quiet, this amphibian, which is one to two inches in length, bears a surprising resemblance to the Spotted Toad. IVhen climbing or when examined closely, its long legs and the discs on its toes readily identify it. The back is brownish or gray in color with dark dots. The legs are barred with dark areas and in addition, the rear legs contain considerable orange on top which fades beneath. The skin is slightly rough, wrinkling to form a prominent fold across the breast. There is a noticeable webbing between the fingers. The call has been described as resembling the quack of a duck or the bleat of a goat.

Food and Habits: In common with other amphibians, the Desert Tree Toad is largely insectivor­ ous. It inhabits rocky canyons in the arid Southwest where it breeds from March through June. The eggs occur singly and are de­ posited in shallow pools where they are usually attached to leaves or other vegetation float­ ing in the water. The tadpoles are about two inches in length and dark olive in color with the tail crests of some suffused with orange or red. The adults ap­ pear from June to about the mid­ Desert Tfoo Thod shoeorng c//sos on foes dle of August, and spend much of the time on the ground.

Range: This toad ranges throughout most of the southwest­ ern United States from Utah to northern Lower California, east to Texas, and in Mexico south to Guadalajara and Toluca.

Distribution in the Park: Most numerous in the Upper and Lower Sonoran Life Zones, the Desert Tree Toad is of fairly common occurrenoe about moist places in the Canyon up to the 15

level of the South Rim. It is reported as especially abundant around pools below the falls in Havasu Canyon.

Features of Interest: Aided by the discs on its toes, this amphibian is capable of climbing a vertical sheet of glass. A common characteristic is its habit of remaining motionless on the face of a boulder along a stream bed, depending upon its protective coloration to escape notioe.

Reptiles

HE great group of reptiles includes the lizards, snakes, turtles, tortoises, alligators and crocodiles. Of theseT, only lizards and snakes have been recorded in Grand Canyon national Park. As' with the majority of animals, the presence of food, water, enemies, and favorable climatic condi­ tions governs the distribution and numbers. Temperature i3 of particular importance as reptiles, in general, require rela­ tively high temperatures and a yearly high mean for optimum activity. Their sensitivity to temperature is due to the fact that they are "cold blooded", or that the body temperature is governed by that of the surrounding medium. In cold weather, reptiles go into a state of dormancy or hibernation during which body activities are at a very low ebb. This condition cannot be maintained indefinitely, therefore reptiles are scarce or absent in regions where winters are long. This ex­ plains the laok of reptile life at the highest elevations of the North Rim area. Neither are reptiles able to endure ex­ tremely high temperatures, and in regions of great heat they seek burrows or shade during the hotter portions of the day. Exposure to the direct rays of the sun for any great length of time may result in death. In regions of excessive heat, some reptiles enter a summer dormancy or aestivation. As previous­ ly explained in the paragraph on life zones, there is consider­ able variation among species as to optimum temperature require­ ments. ,Some species congregate in "dens" during the hiberna­ tion period. Whether this is a social manifestation or a selection of the most desirable location by many individuals is unknown.

As reptiles are best suited by their requirements to live in the relatively warmer portions of the earth, it is to be expected that in arid sections they must have protection from the dessioating effects of the atmosphere. Body moisture is IB

conserved by the scale-covered skin. Students of reptiles have determined that scalation is an aocurate key to the evolu­ tionary relationship of reptiles, hence have established it as a basis for scientific classification. For the purposes of this publication, identification by 3calation is considered as too technical to interest the average reader, so has not been brought into the disoussion.

In arid regions, water sources serve as congregation spots for animal life and in this respect the reptiles are, perhaps, no exception. Reptiles also obtain moisture from rain, the bodies of their prey, and underground sources which they are able to reach.

From the evolutionary standpoint, reptiles are of particu­ lar interest because of their breeding habits. In the major­ ity of cases, reproduction takes place by means of eggs which are deposited in sandy places and covered with sand by the female to be incubated by the heat of the sun. In some cases, however, the young are born alive. This is true, in the park, in the case of the rattlesnakes, garter snakes, and horned lizards. Physiologically, the eggs are merely retained within the body of the female until they hatch, when the young emerge. Thi3 phenomenon has given rise to the false premise, whioh is widely believed, that some reptilian mothers swallow the young when danger approaches, later releasing them.

As a young snake or lizard increases in size, its skin is unable to enlarge with it, hence it beoomes necessary for the reptile to shed the old skin, or molt, at intervals. These molts may occur several times each year. In the case of the rattlesnakes, at each molt a new section is added at the base of the rattle, so the widely credited statement that the age of a snake may be accurately determined by the number of seotions of the rattle, is erroneous. Furthermore, as the rattle be­ oomes longer it is increasingly susceptible to breakage until after a time the sections at the tip of the rattle are often lost about as rapidly as new ones are added at the base.

Reptiles have developed various protective devices to aid them in their fight against enemies. Several species of both snakes and lizards are able to travel rapidly, thus escape by flight. Several species of lizards alter the oolors of their skins, thereby blending with their surroundings. Some rep­ tiles fight viciously if attacked, hissing and striking at the foe. Some lizards strike a heavy blow with the muscular tail. 17

The Chuckwalla has the peculiar ability to inflate its body which it does after crawling into a crevice in the rocks there­ by making its removal very difficult. Several groups of lizards utilize a very peculiar method of escape. They leave a portion of the tail writhing and twisting, in the possession of the captor and scuttle away to safety. Loss of the tail appears to inconvenience the reptile not at all, and on the North Rim of the Grand Canyon at Bright Angel Point where many visitors congregate each summer, numerous bob-tailed lizards are in evidence. As time passes, the lizard gradually grows a new appendage which is usually shorter and has a smoother scal- ation than the original. A few groups of reptiles carry an effective weapon in the form of fangs and poison-secreting glands. This equipment is primarily for the purpose of secur­ ing food and is used for defense only in emergencies. Of the lizards, the Gila (pronounced "hee'la") Monster and a lexican relative, constitute the only poisonous genus known. To date, this reptile has not been recorded in Grand Canyon National Park although it is found in the Virgin River Valley to the northwest. Several groups of American snakes possess poisonous properties, but the rattlesnake is the only genus of venemous snake in Grand Canyon National Park.

In the matter of food habits, the lizards are, in the main, insectivorous. Of those in the park, only the Chuckwalla is a vegetarian. There are several types of lizards that eat other lizards if hungry. The snakes as a group live upon ani­ mals, particularly rodents and for this reason they are of great benefit to mankind, especially in agricultural sections. The unfortunate practice among many persons of killing all snakes on sight has undoubtedly resulted in great loss to farmers. Some species of snakes are known to eat birds, particularly the fledglings and the eggs. The king snakes have derived their name from the habit of eating other snakes. This practice, however, is not nearly as common as generally believed, the king snakes in the main subsisting on small mammals.

In this publication, scientific names and ranges are based upon Stejneger and Barbour, Check List of North American Amphi­ bians and Reptiles, 3rd edition 1933, Harvard University Press. Descriptions and other references are from VanDenburgh, Johnj The Reptiles of Western North Amerioa, Volumes 1 and 2, Occa­ sional Papers No. 10 of the California Academy of Sciences, 1922, except for the rattlesnakes for which the authority followed is L. M. Klauber, A Key To The Rattlesnakes With Sum­ mary of Characteristics, San Diego Society of Natural History, Vol. 8, No. 20, 1936. 18

Lizard*

Banded Gecko Cole onyx variegatus Giaird)

Description: This lizard is a slender, smooth, delicate, semi-transparent creature with small limbs and with hind legs longer than front. The ground color is white to yellowish and the back is crossed by four or five reddish-brown bands which continue the length of the tail. A "U" shaped stripe of ground color runs around the back of the head with arms point­ ing t oward each eye • Two color phases of this species are re­ ported, one as des­ cribed above, the other being spotted rather than banded. There is little chance to confuse this spectacularly marked creature with any other park rep­ tile.

Pood and Habits: Little is known about QcjndGd G&eAo - the habits of the Banded Gecko. It is =n======» apparently insectiverous for in captivity it stalks and cap­ tures flies. Being nocturnal, it is rarely seen. It inhabits areas where Lower Sonoran Life Zone conditions prevail.

Range: Pound throughout the arid Southwest, this speoies is recorded from Texas west to California, north into south­ western Utah; also in northern Lower California.

Distribution Within the Park: The Banded Gecko has been recorded from the Canyon bottom but never above the limits of the Sonoran Life Zones.

Features of Interest: There is a widespread popular im­ pression that this little animal is venomous, but this belief is entirely without foundation in fact. The Geoko is occa­ sionally found in crevices and beneath stones, and when caught may emit a faint squeak. 19

Chuckwalla

Sauromalus obesus (Baird)

Description: Largest lizard in the park and second larg­ est of the United States, the Chuckwalla sometimes attains a length of 18 inches. The head and body are depressed, snout rounded, the tail stout and often bluntly conical. Several neck folds are noticeable. The color is dull brown to black with speckles and blotches of brown, yellow and red creating a lichen-like pattern on the back. On its underparts, the animal is more or less straw-colored with a black chest. The tail is straw-colored and in the young is ringed with dark brown or black. No difficulty should be encountered in identifying this large lizard.

Food and Habits: Unlike the majority of reptiles, the Chuckwalla is strictly vegetarian and consumes the leaves, flowers, buds and sometimes the stems of plants. Rock-loving by nature, it slips into crevices at sign of danger and, if molested, strikes at its t or me nt or with its heavy tail and inflates its body, thereby wedging itself more tightly into the crevice.

Chuck wa/fa _ T. Range: It is found in sou­ thern Nevada, southern California, Arizona, southwestern Utah, northern Lower California, and northwestern Sonora. Distribution Within the Park: This species is found main­ ly within the Inner Gorge but occasionally to the foot of the Redwall Limestone in Grand Canyon. It is a Lower Sonoran type. 20

Features of Interest: When captured, the Chuokiralla may be made to assume a rigid hypnotic position by gently stroking its belly. It may remain in this condition for as long as half an hour. It is able to live successfully even when badly maim­ ed. The Chuckwalla is apparently able to endure greater heat than the majority of reptiles of the same habitat for it is often observed in action in the hot sun, while other reptiles are seeking the shade. The flesh of the Chuckwalla is edible and is considered as a great delicacy by the Paiute Indians, It is said to resemble-the meat of frogs' legs in appearance and flavor.

Western Collared Lizard

Crotaphytus collaris baileyi. (Stejneger)

Description: This lizard is of medium size (11 or 12 inches in length) with muscular body and well-developed limbs of which the rear legs are the longer. It has a noticeably depressed head which appears distinct from the neck because of the prominently swollen temples. The snake-like tail is from one and one-half to two times the length of the body. Nostrils and ear openings are large. In color, it may be olive, sepia-brown, or bluish green, lined and dotted with yellow, gray or white. It is easily identified by the oonspicuous "collar" consisting of two parallel black or dark brown bands separated by gray or white. The underparts are whitish tinged with blue, particu­ larly in the males. This species is easily recog­ nized by the oollar and is not readily confused with Western Collord Lizard any other park lizard.

Food and Habits: This species is notably a rook-loving type. Ordinarily it is quite shy, but if intent on getting food it pays little attention to the presence of man. It has been observed climbing nimbly among the branches of shrubs. 21

On the ground it is swift and agile. It pursues its prey vindictively and, when aroused, is a vicious and passionate fighter. Its food consists mainly of inseots and spiders with a small proportion of vegetable matter and an occasional small snake or lizard. It reproduces by means of thin, soft, membrane-covered eggs. One female is reported to have de­ posited 21 eggs.

Range: The subspecies . C. £. baileyi (not recognized by some authorities) is reported to range through southwestern Texas, southern and western New Mexico, Arizona, Utah, Nevada, Idaho, southeastern California, northern Mexico and Lower California. At the eastern margin of its range, baileyi is reported to merge with £• o_. cpilaris.

Distribution Within the Bark: The Collared Lizard is common throughout the middle elevations of the Canyon in the Upper Sonoran Life Zone. One specimen was collected by the writer on Point Sublime on the North Rim. It is recorded from both sides of the Colorado River, usually not going above 6,000 feet.

Features of Interest: Ditmars reports that this species, when alarmed, may lift its fore legs and run swiftly on its rear legs. Its color is said to be noticeably changeable. It is dull and drab when the animal is cold but brightens up remarkably as the individual becomes warmer and more active. During mating season, there is reported to be a marked change in coloration, the males showing vivid greens while the females become bright pink and salmon on the sides and underparts. When angered, the Collared Lizard shows a bold and fierce dis­ position and puffs out its throat which is dilatable.

Arizona Tree Uta

Uta ornata symmetrica (BairdJ* (Also called the Ornate Swift)

Note: The Utas, of which three species have been identi­ fied in the Park, and the lizards of the Sceloporus group with four representatives in the Grand Canyon, are quite similar in

* Identified by L. M. Klauber. Specimen #87, Grand Canyon study collection. 22

size and general appearance and are easily confused. As an aid to identification, an effort will be made in the descrip­ tion of each species to stress such physical or habitat char­ acteristics as may be of value. In general, the Utas may be identified by the presence of a gular fold or wrinkled skin on the throat. Members of the Sceloporus group do not have this fold. Again, the scales of the Utas are small and rounded while those of the Sceloporus lizards are large, heavily keel­ ed, and end in sharp points.

Description: The Arizona Tree Uta is a small to medium- sized lizard with head and body considerably depressed. The snout is rounded but rather narrow and the ear openings are large. The general color of the upper parts is a grayish or yellowish brown orossed by six to eight light-edged bars of black or brown. The sides are often dot­ ted with blue or yellow and the tail is indistinctly ring­ ed with dusky. Under parts are whitish. Males usually have a blue patch on each side of the belly and an area varying bet­ Arizona 7~n

Food and Habits: Insects constitute the food of this Uta which seeks its prey by running nimbly over the rough bark of trees and shrubs and over piles of stones.

Range: Throughout the Colorado Desert and the Colorado River Valley.

Distribution Within the Park: The Arizona Tree Uta is typical of the Lower Sonoran Life Zone. It is abundant within the Inner Gorge and is found as high on the Canyon walls as the Tonto Platform. Features of Interest: In common with other small lizards. 23

this species is often called "flycatcher" because of its habit of visiting the window screens of human habitations in search of flies and other insects which congregate there. This sub­ species has not been recorded north of the Colorado River.

Rocky Mountain Tree Uta

Uta levis Stejneger* (Also called Cliff Uta, Olive Swift, and Rocky Mountain Tree Swift)

Description: Rather small with rounded snout, and tail less than twice as long as the head and body, the Rooky Moun­ tain Tree Uta is dark gray on its back but becomes paler on head and base of tail. The body is crossed by six to eight pairs of light-edged bars of black or brown either meeting or alternating along the midline of the back. Darker striping usually appears across the top of the head while the tail is indistinctly ridged. The sides show a combination of blue, gray or yellow. Underparts are whitish, dotted or suffused with brown or black. Males usually display a spot of blue, orange, green or yellow on the throat center and a lateral blue spot on each side of the abdomen. The gular fold and small soales identify this lizard as a Uta and it may be dis­ tinguished from other members of the genus by a dark stripe along either side of the head from the nostril, across the eye, above the ear and along the neck where it terminates. It is readily confused with the Arizona Tree Uta and, as the ranges of the two overlap within the Grand Canyon, a problem for study is provided here.

Food and Habits: Although its name suggests the opposite, this Uta prefers the faces of cliffs and sides of rocks to trees, and it is usually found in rocky places. It is not especially wary, and will watch an intruder curiously. Its food consists of insects, particularly flies, ants, and soft- bodied larvae.

Range: It occurs in New Mexico, western Colorado, and southern Utah.

* Identified by A. H. Wright, Specimen #16, Grand Canyon study collection. 24

Distribution Within the Park: Although common at the Canyon bottom, the Rooky 1'ountain Tree Uta has also been ool- leoted on the North Rim, indicating that it ranges through the Lower and Upper Sonar an Life Zones.

Desert Brown-Shouldered Lizard Uta stansburiana ste.jnegari Schmidt* (Also called Sand Lizard and known locally as Flycatcher)

Description: One of the smallest reptiles of the Park, the Brown-shouldered lizard rarely exceeds a length of two inches and the tail is usually less than twice the length of the body. Although there is a great variation among indivi­ duals in color pattern, the ground color is usually gray or brown, striped, mottled or spotted with blue, green, brown, yellow or gray. There is usually a small brown spot in front of the shoulder and a roundish indigo spot on the side behind the arm. The underparts are yellowish white, usually tinged with blue or green on the throat and sides of the abdomen, and more or less mottled along the edge of the throat • Alth ough easily confused with the young of other species, it may be identified by its small size, habit of hiding if disturbed, the single broken stripe from the eye continuing to the tail and by the dark blotoh under the arm. Dtasorf Brown-shov/o'arGo' L/T.crro' The mottling which consists of light dots on a darker ground color is unique.

* Specimen #84, Grand Canyon study oolleotion, was identified by L. M. Klauber. 25

Food and Habits: This species prefers a ground habitat and is at home among the sand and rooks where it digs a burrow for itself using its forefeet and head. It is known locally as "Flycatcher" because of its insect diet.

Range: The Brown-shouldered Lizard ranges from western Texas and northern Mexico through New Mexico and Arizona to the coast range in California, northeastern Lower California, and Angel de la Guarda Island.

Distribution Within the Park: This species is abundant in boulder-strewn areas in the Canyon, and probably comes up to the foot of the Redwall. It is a resident of the Lower Sonoran Life Zone. Features of Interest: This little lizard makes an inter­ esting pet and is usually busy about house and garden captur­ ing flies, ants, beetles and spiders. Often observed lying quietly in the sand or on a rook, it is usually thought to be "sunning itself". Probably, however, it is lying in wait for an insect to approach olose enough to be snapped up. This lizard is notable for its remarkable variation in color pat­ tern whioh makes identification puzzling. It is reported to "play 'possum" if oaught. The tail is very easily broken which often enables the animal to esoape leaving a portion of its tail in the possession of its oaptor. This species, in common with many others, has an interesting habit of "pumping" or raising and lowering the body rhythmically with its fore legs.

Sagebrush Swift

Sceloporus graciosus graciosus (Baird and Girard)*

Description: The Sagebrush Swift is a medium-sized lizard totaling from three and three-fourths to four and one- fourth inches in length. Its color above is gray, olive or brownish and may be tinged with blue or green. Usually a striped effect is due to three darker lines running along the body from each side of the head. These are usually joined on the forepart of the head by three similar oross lines. Under-

* Specimen #44 of the Grand Canyon study collection is identified as this species. 26

parts are white or yellowish tinged with blue on each side of the abdomen.

This species may be segregated from the Utes by the absence of the gular fold (see note on Arizona Tree Dta) and the coarser sca- lation. It is very similar to the Blue- bellied Swift with Scrjcfjrush ^iv/ft. whioh it is easily confused. The latter is a trifle longer, has larger scales, and lacks the diffused blue and mottling on the sides, and the two lateral blue spots. The Blue-bellied Swift also lacks the striped effect characteristic of the Sagebrush Swift.

The Sagebrush Swift may also be confused with the Striped Swift, however, the striping of the latter is lighter than the ground oolor, whereas the stripes of the Sagebrush Swift are less marked and slightly darker than the general coloration.

Food and Habits: Although the Sagebrush Swift is consi­ dered a ground dweller, it is much at home in the branches of shrubs and small trees where it scurries for protection when disturbed. At night it buries itself in loose soil or sand. It is found throughout several life zones from the low desert hills to elevations of 7,000 feet above sea level. Eggs are probably laid in early July. The Sagebrush Swift is a vora­ cious feeder, eating any insect available.

Range: Reported from Oklahoma to California, Utah, and Nevada. Distribution within the Park: The Sagebrush Swift is re­ corded from both rims of the Grand Canyon and from Bright Angel Canyon beneath the rim. It is one of the common types seen by visitors on Bright Angel Point, North Rim.

Features of Interest: This Swift consumes great quanti­ ties of insects including grasshoppers and ants. It is re­ ported, in turn, to serve as food for Crotaphytus wislizenii. a relative of the Collared Lizard, where their ranges overlap. 27

Striped Swift

Soeloporus consobrinus consobrinns (Baird and Girard)*

Description: Similar in size and general appearance to the Sagebrush Swift, the Striped Swift has a somewhat flatten­ ed head and body. The general color above is brown, olive, bluish-green or yellowish with light greenish or yellowish- white stripe along each side of the back from the neck to the base of the tail. A second light stripe separated from the one above by a dark brown stripe runs along the side from the ear to the hind leg passing just above the arm. A dark line from the eye to the ear is usually apparent. The tail is much the color of the back. Lower surfaces are yellowish white, more or less suffused with grey, slate or black. In the males, there is a blue patch on each side of the throat and an elon­ gated blue patch on each side of the belly. This Swift may be confused with both the Sagebrush Swift and Stejneger's Blue-bellied Swift. It is heavier bodied than the Sagebrush Swift and its striping is lighter than the ground color where­ as the stripes of the Sagebrush Swift are darker. The Blue- bellied Swift is not as a rule noticeably striped, although specimens from Utah are reported to be almost indistinguish­ able from the Striped Swift. It may be distinguished from the various species of Utas by the absence of the gular fold and by its coarser scales. (See note on Arizona Tree Uta).

Food and Habits: Robber-flies, ants, beetles and other insects constituted the stomach contents of specimens of this species which have been examined. It is a ground dweller, although it occasionally resorts to trees and shrubs. It usually retreats for protection to holes or the spaces between stones. A report from the Park (Grand Canyon Nature Notes, Vol. 9, No. 3, p. 285) records the eating of an Arizona Tree Uta by a Striped Swift.

Range: Found from the Dakotas southward to Texas and westward to California.

* Specimens #7, #10, #108, and #199 of Grand Canyon study collection. Specimen #7 identified by A. H. Wright as Sceloporus consobrinus. CM. Bogart classes them as S_. undulatus tristichus. 28

Distribution Vftthin the Park: The Striped Swift is re­ ported as common on both rims of the Grand Canyon as well as in side canyons leading down from the North Rim. It is a dweller of the Upper Sonoran and Transition Life Zones.

Stejneger's Blue-Bellied Swift

Soeloporus elongatus Stejneger* (Also Steineger Blue-bellied Lizard and Painted Desert Swift)

Description: Steineger Blue-bellied Swift is noticeably long between the limbs and has a tail about one and one-half times as long as the combined head and body. The hind legs are nearly as long as the body. The color is grayish brown above tinged with yellowish to greenish and interrupted by ^^^^^______^^_^^^^^^^^^^__^^^_ brown or black mark­ ings . In the young, there is an indica­ tion of three later­ al stripes on the side of the head reaching to the neck and shoulders. Un­ derpants are whitish or yellowish with a St^/nectar's B/uo~B^///«d s*>/'ff blue spot on each side of the abdomen and on each side of the throat, although the latter sometimes are lacking in females. This species is readily confused with the Sagebrush Swift and the Striped Swift. It may be distinguished from them by the absence of stripes, although specimens from Utah are reported to be very similar to the Striped Swift. From the Utas it may readily be distinguished by the absence of the gular fold and by the coarser scales. (See note under Arizona Tree Uta).

Food and Habits: Whereas both the Sagebrush Swift and the Striped Swift are ground dwellers, the Blue-bellied Swift is more at home in trees and among the rocks — a characteris-

*Specimons §Q and #9 of Grand Canyon study collec­ tion identified as this species. 29

tic which aids in its recognition. It is not shy, and will cling to the side of a rock or the bark of a tree and watch the passer-by with curiosity. The young are reported to ap­ pear in August. This species is insectiverou3 and stalks its prey with care; often it digs into the ground for insect larvae.

Range: The range of this species is given as northern Arizona and southern Utah.

Distribution Within the Park: This is one of the most widely distributed Canyon Lizards being recorded throughout the area from the Canyon bottom to both rims.

Interesting Features : Like the White man, the Indian has many superstitions regarding reptiles and attributes to some of them powers of a strange and frequently injurious nature. Of the Blue-bellied Lizard, the Hopis say, "This one, if you handle him, when you go on a journey you get very thirsty".

Desert Scaly Lizard

Sceloporus magister Ha Howe 11

Description: Considerably larger in size than other mem­ bers of the Sceloporus group in the Park, this species is covered with rough, coarse scales of a spiny appearance whioh readily serve to identify it. The snout is short and round­ ed, and the limbs are strong and well developed. Upper parts are mottled with yellow, blue, green, black, brown, gray and orange, producing a blotched brown effeot. The sides are marbled with blue, gray, olive, yellow, orange and brown. There is a black blotch in front of each shoulder and a brown area in front of the thighs. Three lateral lines or stripes are indicated on the head and neck. Underparts are lighter than the upper surfaces, and there is a blue or greenish area on the throat adjacent to whioh is a dark blotch or oollar which passes upward in front of the shoulder but does not reach the top of the neok. A barred effect may be noticed on the side of the tail.

Food and Habits: In contradiction to its name, this lizard is seldom found in the open desert but haunts the vLoi- so

nity of small trees and shrubs which it climbs nimbly when disturbed, keeping the trunk or branch between itself and the intruder. On the ground it is said to run swiftly raising the tail above the level of the body. It frequents yuccas and the Opuntia cactuses from whose thorns it is protected by its heavy scales. Flies and ants are said to be favorite foods although all insects are consumed with great avidity. Small amounts of vegetable matter, largely flower parts, have been found in stomachs of this species indicating herbivorous tendencies.

Range: The Desert Scaly Lizard has been collected from southeastern California, western Arizona, southern Nevada, southern and eastern Utah, and northwestern Lower California.

Distribution Within the Park: Although normally it sel­ ects a Lower Sonoran habitat, this species has been observed on the South Rim at an elevation of 7,000 feet. It is abund­ ant in the Canyon bottom.

Features of Interest: The young of this species is reported to be preyed upon by the lizard Crotaphytus wislizenii and by the Road Runner, a desert bird, in areas where these animals are found. It is also attacked by parasitic nematodes. Individuals of this species sometimes attain a length of 12 inches. The Hopi Indians say of the Desert Scaly Lizard, "This one have poison. Mustn't play with him, he make you nervous". Standing on a rock silhouetted against a blue Arizona sky, the sun flashing in bronze and deep blue from its scales, this creature presents a fierce, almost majestic appearance. Only Dasorf Sca/u /-/Z£7rd its small size dispels the illu­ sion of a fire-breathing dragon of the story books. 31

Short-Horned Horned Toad

Phrynosoma douglassii hernandesi (Girard) (Also Horned Toad and Arizona Short-horned Horned Toad)

Description: This little creature has a much flattened body and a shcrt, stubby tail making it look very different from other lizards. A peculiar lateral fringe of rough scales partially encircles the body, and the head bears bony spines which give the animal its name. There is much variation among individuals as to color, some showing an interesting pattern of many hues while others are drab gray or brown. In general, the colors above are gray, yellow, brown, olive or reddish and there is usually an indefinite line down the center of the back separating two series of irregular dark blotches. A dark blotch also appears on either side of the neck. It is usually mottled beneath with a whitish or yellowish ground color, occasionally ranging toward slate.

Considerable confusion exists as to what subspecies is found in the Park. There is some evidence that Horned Toads of the North Rim area are P. d_. ornatissimum (Girard). The consensus of opinion indicates, however, that this latter sub­ species, although ranging to the north, whereas P. _d. hernan­ desi is a southern type, is a desert variety found in the lower, warmer environment of the Painted Desert and to the north of the Grand Canyon area. P. d_. hernandesi is identi­ fied with the pinyon-juniper and Ponderosa Pine associations of the Upper Sonoran and Transition Life Zones. Until further evidence bearing on this question is advanced, it seems safer to take the stand that hernandesi is the subspecies found on both rims, even though it is contradictory to the theory that the Canyon acts as a barrier to the distribution of small animals. The solution of this problem offers a most interest­ ing project for some herpetologist.

Food and Habits: This speoies is a plains, desert and mountain dweller being found up to an elevation of 9,000 feet in Utah. It is the one species of lizard found in the Park which gives birth to living young, the remainder producing by means of eggs. From eight to fourteen young are born, usual­ ly late in July or August. One specimen is recorded which gave birth to 30 young on July 27. Horned toads are mainly insectivorous prefering ants and other small insects although they have been known to attaok large beetles and even snails. 32

One is recorded as eating the young of its own kind (Grand Canyon Nature Notes, Vol. 4, Ho. 1), Range: The range of this subspecies is given as the pla­ teau region of Colorado, southern New Mexico, southeastern and central Arizona, southwestern Texas, and northern Sonera.

Distribution Within the Park: A dweller of the Upper Sonoran and Transition Life Zones, the Horned Toad is abundant on both rims of the Grand Canyon in the wooded areas, but has never been recorded from within the Canyon walls. During August, the abundance of young encountered along the trails of the North Rim area attracts much attention from visitors.

Features of Interest: The horned toad is one lizard to which the Hopi Indians attribute beneficial characteristics. According to one man: "Old folks say if you tie string around neck of Machah-quah and you have hurt, then put him on hurt, you scratch him with hurt, then you get well. If women catch Machah-quah and tie beads around his neck, they have many children."

By gently stroking the underparts of this little ani­ mal, it may be made to assume a rigid position indicating hypnosis. Another interesting feature occasionally reported is the peculiar ability of certain individual horned toads to eject blood from the corner of the eye, VanDen- burgh states that in practic­ ally all cases where this phenomenon has been recorded, the individual was molting.

Although capable of exis­ ting for a long time without water, the horned toad will 5norHHorneH Horn Toad drink greedily when thirsty. The widely-credited legend that horned toads may exist for many years incarcerated within rocks or other prisons is, of course, without any foundation in fact.

When attacked, the horned toad may puff itself up and 33

lower its head presenting its horns. On several occasions, the writer has encountered individuals which would rush at his foot with mouth open, hissing viciously.

Sonoran Whiptail Lizard

Cnemidophorus gularis Baird and Girard (Also called Spotted Race Runner)

Description: This is a long, slender lizard with the tail usually about twice as long as 'the head and body combined, making the over-all length about nine inches. The ear open­ ing is noticeably large. The color of the upper parts is brown with four light bluish, greenish, or yellowish narrow longitudinal stripes along each side,with a similar but faint­ er line down the middle of the back. Old individuals show a spotted .appearance. The head is dark brown or olive. un- derparts are yellow­ ish or bluish white. The tails of young Sonoran Wh/pfa// L/xara specimens show bluish or greenish coloration which darkens with age. This species is not readily confused with any other because of its large size and long, slender tail. It may be definitely identified by a patch of much enlarged scales or granules on the back of the forearm. Food and Habits: Beetles, ants and other insects consti- •tute the' food of the Sonoran "whiptail Lizard. It is a ground dweller and so fleet of foot that it can usually escape from its enemies by flight. Females deposit eight to twelve eggs, burying them in sand or soil.

Range: Considered a dweller of the Lower Sonoran Life Zone, this species is found from Arkansas and Oklahoma through Texas west to Arizona; also in the northern states of I/iexico.

Distribution Vfithin the Part: Very few specimens have 34

been collected in the Park. It is known to be present about Roaring Springs near the upper end of Bright Angel Canyon. Features of Interest: This species exhibits a gradual change in coloration, darkening with age. The longitudinal striping gradually gives place to a dark transverse barred effect. It may be distinguished from the Desert Vfliiptail Lizard by the striped effect of the back and sides, and by a sharp dividing line along the sides between the dark upper and light lower parts.

Desert Whipta.il Lizard

Cnemidophorus tessellatus tessellatus (Say) (Also called Tiger Lizard and VVhipjack)

Description: Although somewhat similar in general ap­ pearance to the Sonoran iYhiptail, this species does not show the striped effect except in the young which are brown above with two light bluish, greenish or yellowish lines extending from the head on each side of the back. In later life, these are broken up into transverse bands on the sides, limbs and tail giving the lizard a checkered or mottled appearanoe. The top of the head is brown, the underparts creamy white tinged with blue gray, and the throat is usually suffused with slate or gray. The mottled effect of the sides, sooty underparts, and lack of striping serve to distinguish this species from the Sonoran Vfliiptail. Food and Habits: The Desert Vfliiptail is a ground dweller and uses its speed to escape its enemies . It is reported to hold the tail in air when fleeing. It is found in semi-desert areas, in open or brushy lands and along stream bottoms. It is usually quite shy. Eggs are laid during late Voserf Wh/pfa// L/z.

Range: This species is recorded from Texas to California, Utah, Colorado, Nevada, Lower California, and adjacent region of Sonora (Guaymas).

Distribution Within the Park: Although quite common within the Canyon bottom, this species has not been reported above the Redwa 11,apparently prefering Lower Sonoran conditions. Interesting Features: The Desert Whiptail has a peculiar habit of running swiftly for short distances, then creeping forward in jerky fashion and dragging its tail , leaving a characteristic track. It frequently digs holes in the sand or soil by scratching with the front feet, then turning around and pushing the dirt out. Scales of the tail differ from those of the body. A Hopi legend states that this lizard chases people and may bring about their death.

Many-Lined Skink

Eumeces multivirgatus (Hallowell)*

Description: The body is cylindrical with limbs small and far apart. The color is pale olive, green, or gray, lighter beneath and on the sides. It has a broad central olive band bordered on each side by Many-Lincc/ Sh/'nM five dark brown and four pale olive stripes. The first and fourth of the dark stripes are the widest. Food and Habits: Ant larvae constitute the principal food.

Range: This species ranges through the central states, Nebraska to Kansas and from the Mississippi Valley to the Rooky Mountains .

* Specimen #206 Grand Canyon study collection identi­ fied by E. H. Taylor. See: University of Kansas Soience Bulletin #23, p. 599. 36

Distribution Within the Park: Unknown, only one indivi­ dual collected (South Rim in dry, open country near Pasture Wash) • Features of Interest: Far outside the limits previously considered as its range, the presence of this species in the Grand Canyon affords an interesting project for study.

Snake*

LTHOUGH not a true differentiating characteristic, absence bf legs serves to distinguish the snakes from thAe lizards of Grand Canyon National Park. Lizards are much more abundant in the Park and, during the summer months, are seen at every turn of the trail whereas snakes are rarely en­ countered. A dislike or fear of snakes is common among many persons, especially women. Humbers of visitors are hesitant about wandering far from their oars because of their belief that they will encounter a snake. This fear is groundless as very few snakes are seen in the Park and of these only one genus, the rattlesnake, is poisonous. Anyone at all willing to increase his knowledge of the out-of-doors will find a study of the snakes most interesting and his fear and distrust of them correspondingly decreased.

Western Striped Racer

Coluber taeniatus taeniatus (Hallowell) (Also called Whip Snake)

Description: The Striped Racer is a very active reptile, long and slender, sometimes reaching a length of five feet. The ground color i3 yellowish with brown or slate-colored lines along the neck coalescing to form a broad stripe down the middle of the back. Four lines along the sides join about two-thirds of the way back to form three stripes. The tail presents a mottled appearance. The color of the underparts is yellow grading into pink toward the tail. The head is us­ ually brown above but yellow below with brown spots on the 37

sides. This racer is easily distingu­ ished from any other park reptile.

Food and Habits: Although a ground dweller, the Western Striped Racer is muoh at home among the tranches of shrubs and small trees in thickets where, if disturbed, it will coil itself about the branches and resist Western Strjpecf Ttacer capture to the utmost. ^——^—= *^™^^—^» It is often found in sagebrush areas, and v/ill move with swift­ ness to reach the protection of brush. If unable to attain cover, it will lash about vigorously with body and tail and will even attempt to bite. Its eggs normally are laid in August. Its food consists of rodents, lizards, young birds and eggs.

Range: The range of this subspecies is from Idaho and Utah southward to the border states, just entering Texas and California.

Distribution Within the Park: The Western Striped Racer is common to the Canyon bottom and stream courses within the walls. It is rare above although it has been observed on both rims . Features of Interest: The name Whip Snake has been ap­ plied because of the great length of the reptile in contrast to its small diameter, and because of its practice of lashing about when attacked. Its value to farmers in destroying rodents is probably nullified by the birds and eggs it con­ sumes. McKee states (Grand Canyon Nature Notes, Vol. 14, No. 1, p. 5) that of 20 snakes identified at the Hopi Snake Danoe, nine were gopher snakes, seven rattlers, and four were racers. 38

Western Patch-Nosed Snake

SaIsadora grahamiae hexalepis (Cope)

Description: This is a slender, smooth-scaled snake with a broad-striped appearance, usually three or three and one- half feet in length with a slender tail. The rostral or nose scale turned up over the other scales is an identification feature which gives it the name. The ground color is light brown or gray modified with darker brown or blackish stri pings. The top of the head is brown, becoming pale behind and narrow­ ing to a line or stripe two to four scales wide. Underparts are yellowish.

Food and Habits: Little is known regarding this snake which is apparently limited to the Lower Sonoran Life Zone. It is a ground dweller, but has been observed among the shrubs. Pack reports one digging a hole by thrus­ ting in the head and, with the neck bent in "S" shape, digging out the loose sand. Eggs are pro­ bably deposit­ ed in Augus t • Food habits are believed to be similar tYesfo/'n Pcrfc/t-nosec/Snake to those of the raoer3.

Range: This species ranges from Utah southward through all of the border states and into ilexioo as far south as the State of Hidalgo.

Distribution Within the Park: Although rare in the Park, the Fatch-nosed Snake has been collected on the Tonto Platform several times. 39

Desert Gopher Snake

Pituophis catenifer deserticola Stejneger* (Also Great Basin Gopher Snake, Utah Gopher Snake, Bull Snake, Blow Snake and others.)

Description: The Gopher Snake of which two subspecies are recorded in Grand Canyon Rational Park, is the commonest snake of the Park, as well as the largest. It sometimes at­ tains a length of five or six feet. The body is largest in the middle, tapering in both directions. The ground color is light brown or yellowish gray and this subspecies is marked with a series of 47 to 66 dark blotches along the back which more or less coalesce at the front of the body but at the rear are separate and form cross bars which extend onto the tail making 12 to 21 rings. Smaller alternating dark blotches ap­ pear on the sides. Underparts are whitish to yellowish more or less spotted with brown. A definite brown line crosses the head from eye to eye behind which line are many irregular brown dots. This subspecies is very similar to the Arizona Gopher Snake but, so far as now known, is limited to the north side of the Canyon. The Ari­ zona Gopher Snake has only 37 to 55 blotches on the body and from 10 to 14 rings on the tail, and occurs south of the Canyon bottom.

Food and Habits: Gopher Snakes are found commonly in the vicinity of brush and trees, or about buildings frequented by birds and rodents. They feed upon eggs, young birds, and ex­ tensively on ground squirrels and other rodents. The eggs, JDeaert Gopher Snake laid in July, are deposited in sand, frequently in layers, with several inches of sand covering them.

•Specimens #46 and #148 of the Grand Canyon study col­ lection were identified by L. M. Klauber as Pituophis catenifer 3te.1neeerl. 40

Range: The subspecies desertioola is found in desert re­ gions of southern California, Nevada, and Utah, south to Idaho and the eastern parts of Oregon and '.Vashington.

Distribution Vtithin the Park: Reported only from the Worth Rim area, where it is found in the Upper Sonoran and lower elevations of the Transition Life Zones. Features of Interest: The gopher snake is of notable value to farmers in ridding their premises of rats, mice, gop­ hers and other rodents. As a rule, gopher snakes are gentle and do not resent handling.

Arizona Gopher Snake

Pituophis sayi affinis (Hallowell)* (Also called Bull Snake and Blow Snake)

Description: Although very similar in general appearance to the Desert Gopher Snake, this reptile may be identified by the fewer number of dark blotches on the body and by fewer rings on the tail (see description of Des ert Gopher Snake). As this form does not occur north of the bottom of the Canyon where­ as the range of the other does not extend south of the Colorado River, the loca­ Arizona Gopher Snake tion in which a snake is found apparently is sufficient to identify it. * Speoimens #31 and #55 in the Grand Canyon study col­ lection are identified as Pituophis catenifer rutili3. while #248 is listed as P. s. affinis. Vandenburgh uses the former nomenclature. 41

Food and Habits: These are the same as given for the Desert Gopher Snake. Range: This form is found in southern Colorado south to Chihuahua, I.'exico, west through Arizona and southern California and south to the Colorado Desert in Lower California.

Distribution Within the Park: The Arizona Gopher Snake is found throughout the south rim area and occasionally within the canyon walls as low as the Tonto Platform and is one of the commonest snakes of the Park. It is a resident of the Upper Sonoran Life Zone.

Features of Interest: Observers at the Hopi Snake Dance ceremonies report that the Arizona Gopher Snake is one of the reptiles used most commonly in this spectacular ritual.

In farming districts, the Arizona Gopher Snake is of con­ siderable value to man in destroying undesirable rodents.

Arizona King Snake

Lampropeltis pyromelana (Cope)* (Also called Coral King Snake)

Description: This spectacular reptile is usually from 20 to 30 inches in length and is characterized by brilliant red, black, and cream-colored bands, each, one to three scales in width, extending around the body. The black bands may or may not entirely encircle the body and may or may not coalesce on the hack. The banding occurs in the order: white, black, red, black, white, black, red, black, etc. The red between the black hands usually crosses the abdomen. This species can hardly be confused with any other Park reptile. It may easily be distinguished from the Boyle's King Snake by the absence on the latter of the red bands; from the Bicolar Ground Snakes by the Ground Snake's lack of white bands.

Although the venemous Coral Snake does not occur within Grand Canyon National Park, so far as known, the great simila­ rity in appearance between it and the Arizona King Snake is 42

worthy of note. Genetical­ ly these snakes belong to very different groups, so this likeness is considered by biologists as a fine example of mimicry or imita­ tive coloration from which the Arizona King Snake bene­ fits. The Coral Snake is marked by bands of red, white and black. In it, however, the red bands occur between the white bands, Ar/zona t4/n

Food and Habits: Very little is known regarding the food or habits of this rather uncommon reptile. In Utah, it is found at elevations of from 5,400 to 7,000 feet and is con­ sidered a resident of the Transition Life Zone.

Range: The King Snake of the North Rim area of Grand Canyon National Park is generally considered the same as the Coral King Snake (Lampropeltis pyromelana Cope) of the coni­ ferous forests from northern Mexico through southwestern New Mexico and the higher elevations of Arizona.

Boyle'* King Snake

Lampropeltis eetulus boylii Baird and Girard* (Also Boyle's Milk Snake, Pacific King Snake, and Chain Snake)

Description: Boyle's King Snake is usually from three to four feet in length and is banded with black and white. There is little constriction at the neck and the snout is broadly rounded. The blaok or deep brown bands are widest on the upper parts, while the white, or ivory bands are widest be­ neath. The bands often run obliquely around the body and

* L. M. Klauber states that this form is now known as L« £.• oalifofniae 43

number from 23 to 39 on the body and from 5 to 10 on the tail. The head is black except for the snout and cheeks •which are •white and the lips which are yellow. This species is not easily confused with any other Park reptile.

Food and Habits: Somewhat nocturnal, this King Snake in­ habits canyon bottoms and brushy stream banks where Lower Sonoran Life Zone conditions prevail. It usually has a docile disposition but is reported to fight viciously when annoyed. Its food consists of rodents, birds eggs, other snakes, and lizards. Range: This subspecies is recorded from Arizona, western IJevada and California.

Distribution V/ithin the Park: Boyle's King Snake is a common resident of the Canyon bottom and has been collected also in Havasu Canyon.

Features of Interest: These reptiles are called King Snakes because of their mastery over other species of reptiles, but they do not attack other snakes on sight as is widely believed. If very hungry, they will consume other reptiles. The pre­ sence of the Boyle's King Snake in the Canyon bottom coupled with its range to the south and west brings up the question as to whether or not its entrance or avenue in­ to this area has been Bocj/c's Kina Snake through the course of the Canyon from its western extremity. 44

Bicolor Ground Snake

Son or a semiannulata Baird and Girard Description: Although somewhat resembling the Arizona King Snake because of its conspicuous colors and their arrange­ ment in bands encircling the body, the Bicolor Ground Snake is much smaller and the bands are only of black and red. The head is short and flat on top with the snout projecting beyond the lower jaw. The blaok bands pass over the baok usually fading at the edge of the abdomen and the red fades to pink or yellow beneath, so that the under- parts are yellowish or greenish white. A broad black band covers most of the top of the head reaoh- ing to below the eye. The S/co/or Ground Snake top of snout and the lower jaw are red.

Food and Habits: Very little is known about this small reptile. The shape of its snout and the known activities of its relatives indicate burrowing habits. It is usually noc­ turnal, which makes its collection and the study of its acti­ vities extremely difficult. Range: The species is recorded from Idaho to Utah and Nevada, Arizona, southern Kansas and Texas; also from south­ eastern California and the adjacent regions of Mexico.

Distribution in the Park: The Bicolor Ground Snake has been found at Indian Gardens in the Lower Sonoran Zone. 45

Spotted Night Snake

Hypsiglena ochrorhvnohus oohrorhvnohus (Cope) (Also called Rook Snake)

Description: This is a small, stout-bodied, brown-spot­ ted snake with a short, rapidly-tapering tail. The head is depressed and rather flat on top with a short, rounded snout which projects beyond the lower jaw. The temporal regions appear swollen. The ground color is yellowish white but so speckled above as to have a general brownish appearance. The head is usually spotted with brown and dark blotches over the neck which commonly extend down the sides. This species may be confused with the young of the Gopher Snake, but is identi­ fied by the projecting snout and the spotted appearance. A noticeable black line extends from the end of the nose through the lower part of the eye to the base of the jaw.

Spotted Niaht Snake

Food and Habits: Due to its rarity and nocturnal habits, not much is known regarding this small snake. It is occas­ ionally found beneath stones, logs and brush.

Range: This species is reported from southern and Lower California, Arizona, southern Utah, Idaho, southern Nevada, southwestern Texas, and northern Mexico.

Distribution Within the Park: This rarely-seen snake has been collected only along Bright Angel Creek. 46

Wandering Garter Snake

Thamnophis ordinoides vagrans (Baird and Girard) (Also called Western Garter Snake)

Description: This garter snake is drab or olive in gen­ eral appearance, but on close observation the ground color is seen to be greenish, yellow, olive and brown. TITO series of alternating slate or black spots often occur on each side. A yellow line usually runs along the middle of the back and others along each side but any or all of these may be indisv tinct or absent. In the young, a spotted effect is noticeable but adults are uniformly drab. The head, which is distinct from the neck, is usually brown above and yellowish beneath. The normal size is from 20 to 30 inches.

Food and Habits: Because of their choice of moist locations about small bodies of water, the garter snakes are often miscalled water snakes. Their preference for a moist habitat is due to the plentiful supply of food consist­ ing of frogs, toads, tadpoles, fish and other small animals which frequent a moist environ­ ment. Garter snakes are voraci­ Wanc/ar/nq Gar far Snake ous feeders and consume large numbers of both larvae and adults of the cold-blooded vertebrates.

Range: The Wandering Garter Snake is found from eastern Wash­ ington, Oregon, through Idaho south to northern Arizona and eastern California.

Distribution Within the Park: This snake has been col­ lected from both rims but has not been found within the Canyon itself. It is fairly common at Bright Angel Point on the North Rim, and several specimens have been collected at Green­ land Lake, on the North Rim, at the time that larvae of the Spadefoot Toad are most numerous there. Since the Wandering Garter Snake is recorded from both rims yet is absent from within the Canyon, it offers contradictory evidence to the 47

theory that the Canyon acts as a barrier to reptiles. Close study, however, may show constant differences between speci­ mens from opposite rims, thereby providing evidence in favor of the barrier hypothesis.

Interesting Features: Its roving habits have given this subspecies the name of Wandering Garter Snake. One noticeable characteristic of some value in identifying this snake is the "dirty odor", which it has. This may account for the fact that the Wandering Garter Snake has never been observed in connec­ tion with the Hopi snake danoe, although it is thought to in­ habit the area adjacent to the Hopi villages.

Brown-Spotted Garter Snake

Thamnophis ancustirostris (Kennicott)

Description: The Brown-spotted Garter Snake is a long, slender serpent with tapering tail and head distinct from its neck. It is easily identified by its long, narrow, rounded head which is very different from that of the majority of garter snakes. The color of the upper side is dark olive or brown with several row3 of dark-brown spots that become less evident with age. The throat is yellow and the under surfaces of the body are greenish or bluish grey with numerous small blackish dots. The absence of stripes, heavy spotting, and the long narrow head distinguish it from any other Grand Canyon reptile.

Food and Habits : Very little is known about the activi­ ties of this reptile. It is reported as being found about small creeks and canyon bottoms, and seems at home in the water and on the rocks at the edge of streams.

Range: This species has been collected from southeastern Arizona and southwestern Hew liexico south to Coahuila and Durango. VanDeriburgh indicates that it is quite common in Oak Creek Canyon, south of Flagstaff, Arizona.

Distribution "Within the Park: This species has been collected from the South Rim of the Grand Canyon where it is apparently quite rare. 48

Trimorphodon And Tantilla

Although not collected within Grand Canyon National Park, representatives of these genera are probably present in the area. Interested persons should be on the watch for them as knowledge of their presence would add interest to the repti­ lian life of the Park. TANTILLA: Members of this group are small with a head low and flat above and broadly joined to the body. Due to the small size, burrowing habits and nocturnal preferences, repre­ sentatives of this genus are rarely seen.

TRIMORPHODON: Snakes of this group are not often seen for they are largely nocturnal. They range from 15 to 30 inches in length and are blotched in pattern. A pair of en­ larged grooved teeth in the lower jaw indicates venomous ten­ dencies .

Rattlesnake

N Grand Canyon National Park, rattlesnakes offer prac­ tically no danger to man because of their scarcity. FurthermoreI , the bite of the rattlesnake usually is not fatal, statistics showing that only about ten percent of adults bit­ ten actually succumb. The seriousness of the bite depends upon many factors including the size and species of the snake, the amount of poison injected, and the natural resistance as well as the action taken by the victim immediately following the bite. Children are normally much more seriously affected than are adults.

Rattlesnakes are provided with poison primarily to aid them in obtaining food. The poison, secreted by a pair of glands beneath the eyes, is injected by means of a pair of hollow teeth or fangs located near the front of the upper jaw. The reptile, in striking, drives the fangs into the flesh of its prey where they may cling for some seconds. The poison is injected while the fangs are imbedded. As a defense mech­ anism, the poison injecting apparatus of the rattlesnake is very effective and is the basis of the widespread fear in which these reptiles are held by mankind. 49

Although the chance of being bitten by a rattle­ snake is very slight, every per­ son should know the principles of first- aid in case of s nakeb it e , Ant i- venim is a scienti­ fically prepared substance -which will counteract the effect of snake poison within the body. It is only effective, however, after venim has spread through the blood system, lleanwhile a victim of snakebite should attempt to eliminate as much venim as pos­ sible by immediately slashing the flesh at the point where the fangs entered and by applying suction. If no other means is available, sucking with the lips is effective. Suction should be maintained for half an hour or longer. The freer the bleeding and the more thorough the suction, the less poison will enter the circulatory system of the person bitten. The patient, of course, should be kept as quiet as possible, thus slowing the spread of the poison.

Rattlesnakes in common with garter snakes and horned liz­ ards, give birth to living young. In this respect, these genera differ from all other park reptiles.

Contrary to popular belief, the number of rattles carried by a rattlesnake is no index to the reptile's age, a new- rattle appearing after each molt. A snake may molt three or four times a year. The rattles are brittle and, although carried carefully by the snake, usually are broken off at the tip about as fast as replaced, after the rattle has become of some length. Because of the habit of the rattlesnake of sounding its rattle when alarmed or angered, it is considered the "gentleman" of the reptile group. However, a snake will not always rattle before striking.

The extent to which a rattlesnake may strike depends upon its state of anger or excitement, and on several other factors. The distance is usually about half the length of the snake, but occasionally it is three-quarters if the snake is in a frenzy of anger or excitement. 50

In some places in the west, particularly in the prairie states, rattlesnake migrations occur in the fall as the snakes, apparently imbued with a common impulse, move from their summer range to nearby areas affording better winter protection. Rattlesnake "dens" are occasionally encountered. These consist of caves, prairie dog towns or crevices where great numbers of these and other snakes congregate during the hibernation period.

Northern Black-Tailed Rattlesnake

Crotalus molossus molossus Baird and Girard Description: This is a large, heavy-bodied snake reaching a length of three to four feet. It is olive-green or yellow-green In color with dark brown blotches on the back. From other rattlesnakes it may easily be distinguished by the black snout and black tail, the latter ftorfhern B/ocA-Ta//ed fto/f/ezrtdke characteristic giving it it s name.

Food and Habits: Food of the Black-tailed Rattlesnake consists largely of small rodents. It is generally a ground dweller for it is too heavy-bodied to move readily without a substantial support. Range: This subspecies is found from 'western Texas to Arizona and south into liexico to northern Durango. In Arizona it is found from the Grand Canyon and Little Colorado River south into kexico except in liohave and Yuma Counties.

Distribution Within the Park: The northern Black-tailed Rattlesnake is very rare within the Grand Canyon National Park, the South Rim being considered as the northern limit of its range. Only two specimens of this species have been collect­ ed within the Park to date. 51

Great Basin Rattlesnake

Crotalus viridis lutosus Klauber

Description: This subspecies is characterized by a ground color of light brown, gray, buff or drab. The body blotches occupy less or but little more longitudinal space than the interspaces, and toward the tail appear as rings rather than blotches. A secondary series of blotches is little in evi­ dence. The head is triangular in shape and distinct from the neck. Underparts are whitish, yellow or clouded with brown. The snake usually attains a size from 30 to 36 inches.

Food and Habits: Small rodents constitute the major food of this subspecies. It is a ground dweller, inhabit­ ing the arid lands of desert and foothill to an elevation of 7,000 feet in Utah. It is usually found among shrubs, trees and brush. The young are born alive, usually in September.

Fange: The Great Basin Battlesnake, as its name im­ plies, is an inhabitant of the Great Basin region between the Great Basin Etotffesnake Rooky and the Sierra Nevada Mountains. It is recorded from southern Idaho, western and southern Utah, Arizona north and west of the Colorado River, nearly all of Nevada, eastern California, and south eastern Oregon.

Distribution Within the Park: Although- this form has never been collected from within the boundaries of Grand Canyon National Park, it is recorded from Grand Canyon National Monument which adjoins the Park on the west. 52

Arizona Prairie Rattlesnake

Crotalus viridis nuntius Klauber Description: This subspecies is pink, red or red-brown in color, but shows a variation to greenish or grayish on the plateau south of the Grand Canyon. Individuals rarely exceed 30 inches in length. Inasmuch as this is the only form found in the South Rim area (except the very rare Black-tailed Rat­ tlesnake), there is little chance of mistaking its identity.

Food and Habits : Al­ though very little informa­ tion is available regarding the habits of this sub­ species, they are in all probability quite similar to- those of other rattlesnakes.

Range: This form is found throughout northeast­ ern and north central Ariz­ ona from the Hew Mexico line to Havasu Creek, including the following: basin of the dr/zona Prair/a Pafr/e snake — Little Colorado River, south- em part of the Apache Indian Reservation, the Hopi Indian Reservation, and the Coconino Plateau from the south brink of the Grand Canyon south to U. S, Highway 66.

Distribution Within the Park: Although rarely encounter­ ed, this is the rattlesnake of the South Rim area as far west as Havasu Creek. It is known to range beneath the rim.

Features of Interest: The Prairie Rattlesnake is the oommoj.1 rattlesnake of the Hopi Snake Dance. To the herpeto- logist, the place of this subspecies in the systematic rela­ tionship to the various phases of the Prairie Rattlesnake offers much of interest. 53

Grand Canyon Rattlesnake

Crotalus viridis abyss us Klauber

Description: The Grand Canyon Rattlesnake is identified by the fact that the colors of the adult vary from vermilion to salmon with the body blotches tending to become less oon- spicuous or almost absent in older specimens. Range: This subspecies is restricted to the Grand Canyon of the Colorado River between the north and south rims. It has been reported from Cedar Mesa, a short distance beyond the rim of the Canyon to the east. Distribution Within the Park: The Grand Canyon Rattle­ snake is the only reptile so far recorded exclusively from the Grand Canyon. Its range is limited to the area beneath the rims where it is distributed at all elevations, but it is pri-» marily a native of the Lower Sonoran Life Zone. At no point within the Canyon is it abundant, and considerable difficulty has been encountered in obtaining sufficient specimens to make a careful study.

Features of Interest: Because of its limited range, this species has received considerable publicity and is frequently sought by interested visitors to the Grand Canyon. Its dirty pink color causes it to blend well with the reddish rocks and soil which compose many levels of the Canyon walls, hence it is inconspicuous and easily overlooked. 54

Bibliography

Cockerell, T. D. A.} "Zoology of Colorado", Univ. of Colo. Semi-centennial Publ. Vol. 3, 1927.

Ditmars, Raymond L.j "The Reptile Book", Doubleday, Doran & Co., Garden City, N. Y., 1935.

Ditmars, Raymond L.j "Reptiles of the 7/orld", The llacmillan Co., New York, 1933.

"Grand Canyon Nature Notes", Vols. 1 to 9, 1926-35, National Park Service, Grand Canyon National Park, Arizona.

Klauber, L. M.J "Herpetological Review of the Hopi Snake Dance", Bull. #9 of the Zoo. Soo. of San Diego, Calif. 1932.

Klauber, L. H.j "Key to the Rattlesnakes with Summary of Characteristics", Trans. San Diego Soc. of Hat. Hist. Vol. 8, No. 20, 1936.

J/oKee, Edwin D., and Bogert, Charles M.J "The Amphibians and Reptiles of Grand Canyon National Park"; Copeia, No. 4, pp. 178-180, 1934.

Stejneger and Barbour, "Check List of North American Amphi­ bians and Reptiles"; Harvard Univ. Press, Third Ed. 1933.

VanDenburgh, John; "Reptiles of Western North America", Vols. 1 and 2, Occasional Papers, Calif. Acad, of Soi., No. 10, 1922.

Woodbury, Angus A.j "Descriptive Catalogue of the Reptiles of Utah", Bull, of the Univ. of Utah, Vol.21, Ho.5, 1931.

Wright, A. A. and A. H.j "Handbook of Frogs and Toads", Comstock Publishing Co., Ithaca, New York, 1933. Index

Page Page No, No. Ambystoma 9 Prairie Rattlesnake 52 Amphibian ....8 Prehistorio Amphibians. 2 Bibliography 54 Raoer 36 Blue-bellied Lizard 28 Rattlesnake. 48 Brown-spotted Garter Snake..47 Reptile 15 Brown-shouldered Lizard 24 Rooky Mountain Toad. 13 Blaok-tailed Rattle snake.... 50 Sagebrush Swift 25 Bufo 11, 13 Salamander. ...9 Chuckwalla 19 Salvadora 38 Cnemidophorus.... 33, 34 Sauromalus. .19 Cole onyx 18 Soaly Lizard 29 Collared Lizard 20 Soaphiopus 10 Coluber. 36 Soeloporus 25, 27, 28, 29 Crotalus 50, 51, 52, 53 Skink 35 Crotaphytus 20 Snake 36 Eumeoes .35 S onora ..44 Garter Snake 46, 47 Spadefoot Toad 10 Geoko 18 Spotted Toad 11 Gopher Snake..... 39, 40 Striped Raoer .36 Grand Canyon Rattlesnake....53 Striped Swift 27 Great Basin Rattlesnake 51 Swift.; 25, 27, 28 Ground Snake ..44 Tant ilia 48 Horned Toad 31 Thamnophis 46, 47 By la 14 Toad 10, 11, 13, 14 Hyps iglena. ..45 Tortoise 15 King Snake 41, 42 Tree Toad 14 Lampropeltis 41, 42 Tree Uta 21, 23 Life Zones 5 Trimorphodon 48 Lizard 18 Turtle 1, 15 Mud Puppy ..9 Uta 21, 23, 24 Night Snake 45 Wandering Garter Snake 46 Patched-nose Snake. .33 Water Dog .9 Pituophis .39, 40 Whiptail Lizard 33, 34 Phrynosoma...... 31