o/(/ HARVARD UNIVERSITY s®. LIBRARY OF THE Museum of Comparative Zoology 0: NATURAL HISTORY OF THE PRAIRIE DOG N KANSAS RONALD E. SMITH m& COMP. 200U LIBRARY 14 rv °7 . Mf \ N, I -.Ll ^ UNIVERSITY OF KANSAS MUSEUM OF NATURAL HISTOR AND STATE BIOLOGICAL SURVEY University of Kansas Museum of Natural History AND State Biological Survey of Kansas editor: E. RAYMOND HALL Miscellaneous Publication No. 49, pp. 1-39, plates 1-4, figures 1-10 Published September 27 , 1967 [Pages 1-36 are reprinted, by the ofFset process, from Miscel- laneous Publication No. 16 of the Museum series. Addenda by Stephen R. Wylie appear on pages 38-39. — Editor.] PRINTED BY ROBERT R, IBOB) SANDERS. STATE PRINTER TOPEKA. KANSAS 1 967 31-9493 Natural History of the Prairie Dog in Kansas By Ronald E. Smith Museum of Natural History and State Biological Survey University of Kansas University of Kansas museum of natural history AND STATE BIOLOGICAL SURVEY OF KANSAS EDITOR: E. RAYMOND HALL Miscellaneous Publication No. 16, pp. 1-36, plates 1-4, figures 1-9 Published June 17, 1958 PRINTED IN THE STATE PRINTING PLANT TOPEKA. KANSAS 1953 27-2178 NATURAL HISTORY OF THE PRAIRIE DOG IN KANSAS By Ronald E. Smith CONTENTS PACE Introduction 5 History 6 Acknowledgments 7 Methods 7 Description and Distribution 9 F'ooD Habits 10 Behavior 13 Communication 13 Intraspecific Contacts 15 Daily Routine and Feeding Behavior 17 Relations to Weather and Seasonal Activity 18 Relations to Associated Animals 19 Reactions to Observer 22 Molt and Pelage 23 Reproduction 25 BuRROv^^s 26 Population Changes 29 Summary 33 Literature Cited 35 — 3 NATURAL HISTORY OF THE PRAIRIE DOG IN KANSAS INTRODUCTION THE prairie dog has lived on the Great Plains of the United States since Pleistocene times. To the Indians he was import- ant as a source of food, especially when large game was scarce. In the middle 1800's, when explorers, trappers, and pioneers crossed the plains west of the Missouri River and east of the Rocky Moun- tains, the monotony of the long arduous trips was relieved by the antics of the gregarious, small mammal, the prairie dog. Letters and diaries mentioned the animal and frequently contained highly exaggerated accounts of the social structure of prairie dog colonies. With the settlement of this region and the resulting grazing and cultivation, agriculturists made the prairie dog the object of nu- merous eradication campaigns, which through the years have brought about marked declines in numbers of the prairie dog. In 1903, Lantz estimated that prairie dogs inhabited two to two- and-a-half million acres in Kansas, but today they inhabit no more than 57,045 acres and the acreage is being reduced by more than a fourth in the present year ( 1957 ) . At this rate, within ten years the prairie dog in Kansas will be but a conversation piece in the fascinating tales of "varmit hunting" when Granddad, or Dad, was a Httle boy. Even though these stories will be interesting, there will be little scientific information or even accuracy in them. Before these animals are even more drastically reduced in number and pushed into yet more isolated and atypical regions of their range, it seemed, to me, worthwhile to undertake the natural history study here reported on of one of the last "large" prairie dog towns in Kansas. Within limits the prairie dog adapts itself to local conditions; therefore studies in South Dakota or Colorado do not necessarily depict its way of life in Kansas or vice versa. Objectives of my study were: ( 1 ) To determine the distribution and habitat occupied in Kansas, (2) to study the life history of the species, (3) to deter- mine the economic bearing of the prairie dog's activities on enter- prises of man, and (4) to discover factors limiting dispersal and occupation of new habitats. — o My field study was begun in June, 1955, and terminated in June, 1957. The area chosen was a pasture five miles north, and one and one-half miles east of Sharon, Barber County, Kansas, on the Haw- kins Ranch. To my knowledge this pasture contains the most easterly "large" ( more than 40 acres ) prairie dog town in Kansas. This area is of the chestnut soil type and has an average annual rainfall of 25.5 inches. HISTORY The prairie dog was first brought to the attention of zoologists by a skin obtained by Lewis and Clark on their expedition of 1804- 1806, although Pike, 1806-1807, was the first to describe the animal in Kansas and designated it by its Indian name, Wishtonwish. In 1815, George Ord described the animal and named it the Louisiana marmot, Arctomys ludovicianus. In 1817, Rafinesque proposed for it the new generic name Cynomys. Confusion concerning these names and their correct application existed until the publication of Baird's "Mammals of North America" in 1858, when two species, one black-tailed and the other white-tailed were recognized. Allen, in his "Monograph of the Sciuridae" in 1877, also recognized two species. In 1916, Ned Hollister pubfished his "A Systematic Account of the Prairie-dogs" in the North American Fauna series (No. 40), in which he divided the genus into two subgenera and seven species and subspecies. Only Cynomys ludovicianus ludovicianus occurs in Kansas. The first natural history notes on the prairie dog in Kan- sas known to me were made by J. R. Mead in the year 1859 ( pub- lished in 1899 ) in which he wrote, "Prairie dogs were innumerable. The divide between Saline and Solomon in Ellsworth county and west was a continuous dog town for miles; and, as a considerable portion of this locality was underlaid with horizontal beds of shale or hmestone near the surface, it was a mystery where they got water. Not a drop could be found within several miles and none by digging above the rock, and not a particle of dew fell for weeks in the heat of summer. The scant grass was dry enough to burn an hour before sunrise; and I was forced to the conclusion that in this instance nature had constructed an animal capable of living for long periods of time without water. My pen cannot describe the extreme heat and drought which sometimes prevailed on these bare uplands during July and August. . . . The foot of the buffalo was necessary for their existence. As soon as the ground ceased to be tramped hard and the grass and weeds grew they perished." From 1900 to the present the bulk of the literature concerning prairie dogs is in bulletins of agricultural experiment stations and — 6 — concerns destructiveness and control of the prairie dog; however, in 1949, Osbom and Allan published in the magazine Ecology a significant paper entitled "Vegetation Of An Abandoned Prairie-dog Town In Tall Grass Prairie," and in 1955, John A. King published a somewhat different type of study entitled "Social Behavior, Social Organization, And Population Dynamics In A Black-tailed Prairie- dog Town In The Black Hills of South Dakota." C. H. Merriam (1901), Vernon Bailey (1926), and Theo. H. SchefiFer (1937) all wrote about habits and habitats of the prairie dog. "Varmit hunting" or "target practice" has been a Sunday after- noon pastime for more than a hundred years in prairie dog country, and needless to say, if the hunters had been more accurate and the prairie dogs less prolific and less agile, the millions of rounds of ammunition expended in their direction would long ago have placed the prairie dog in the present position of the dodo bird. ACKNOWLEDGMENTS Thanks are extended to Dr. E. Raymond Hall, under whose guidance this study was made. Dr. Henry S. Fitch and Dr. Carl Koford advised me on field methods, and Dr. Ronald L. McGregor identified plant specimens. Special thanks are extended to Mr. Ezra Hawkins for permission to study the dogtown on his ranch and for his cooperation in various phases of the investigation. Special thanks are extended also to Mr. Floyd T. Amsden who pro- vided for me a residence conveniently near the study area; he encouraged me to use the facilities of Plum Thicket Farm, adjacent to the lands supporting the prairie dogs. Mr. Jess Crocker, game manager of Plum Thicket Farm, and his son, Robert, gave me greatly appreciated assistance in the field. Without the monetary support of the State Biological Survey of Kansas, such a study would not have been possible. METHODS The study here reported on was based chiefly on observation and live trapping, and was supplemented by laboratory investigations. Observations were carried on with the aid of binoculars and a 20-power spotting scope. Three blinds were set up and used in regularly observing marked prairie dogs. In addition the prairie dogs became so accustomed to the panel truck that as long as a person stayed inside it, the truck could also be used as a "blind" for making observations. Several types of traps and snares were tried. Best results were obtained with the 9/2 x 9J2 x 24 inch live traps of the National Live Trap Company of Tomahawk, Wisconsin. They are collapsible and constructed of heavy gauge wire mesh. Frequently two animals were caught in one trap at the same time. The traps were baited with oats and usually were tied open for two or three days before they were set. In January, February, and March it was not necessary to tie the traps open because natural food was scarce and the prairie dog readily took the bait. Once an animal was caught, marked, and released it soon became a nuisance, some animals having to be released two and three times a day for as long as the traps were in that locale. Traps were placed around active burrows, generally two traps to a burrow and about three feet from its opening. Only about one acre or less was trapped at a time as it was necessary to concentrate the traps for best results. Captured animals were handled with thick leather gloves, and although the prairie dogs could and did bite through them, rapidly acquired skill in handling the animals soon eliminated this hazard. Each individual captured was weighed and sexed. Most of the animals captured were marked and returned to the field but a few were sacrificed for more complete examination. A data sheet facili- tated the recording of information. Toe-clipping caused considerable bleeding in some individuals, and this method of marking was abandoned early in favor of brand- ing; branding fluid and a small branding iron (one inch long by one-fourth inch wide) were used. The fur was cut oflF by means of a pair of hair clippers before the branding fluid was applied. A variety of symbols could be made with the branding iron, and brands on right or left hind quarter or right or left forequarter gave many possibihties for marking without duplication. In addition animals were marked with dye (Nyazol A, Nyazol Chemical Company) for easy identification with binoculars or scope. The dye seemed not to affect the behavior of unmarked dogs toward marked dogs. In fact, completely dyed, coal-black prairie dogs moved about within the colony without incident and none is known to have been the object of predation. The burrows observed from blinds Nos. 1 and 2 were mapped, and distinctively marked dogs were related to their respective burrows. Temperature, wind velocity, and humidity readings were taken three feet from the ground. Light readings were taken at approxi- mately six inches above the ground. Questionnaires concerning prairie dogs were sent to twenty-one 8 western county agents; many residents of Barber County were in- terviewed or volunteered information concerning present dogtowns in the county or on dogtowns of earlier days. Twenty-three prairie dogs were kept in the animal house on the University of Kansas Campus from January, 1956, to June, 1956, for observation, including study of molt pattern. The animals were transferred to a building used for laboratory work at Plum Thicket Farm in Barber County, Kansas, and remained there until August, 1956. All photographs are by the author. DESCRIPTION AND DISTRIBUTION A thickset, robust, terrestrial, burrowing squirrel; tail short (rarely more than one-fourth of total length), well-haired but flat; ears short, not extending beyond pelage; eyes moderately large, cheek pouches rudimentary; head broad and rounded; molars large and converging posteriorly; legs short, wrist and heel well-furred; a tuft of hair in the center of palm; feet large; claws well-developed, larger on forefeet than on hind feet, five in number on each foot. Mammae eight. Total length of adults 335-430 mm., hind foot 47-60 mm. exclud- ing claw, weight 650-1050 grams (lM-2/2 lbs.). Dental formula 1 . 0 . S . s _ 90 T> 5> l» ff —^i- Upper parts cinnamon bufiF, over-hairs black, underparts and face buffy-white or whitish; terminal third of tail black. Two molts per year; winter pelage longer and having more buff and gray than summer pelage. Prairie dogs are diurnal, her- bivorous, gregarious, and are remarkably curious. The black-tailed prairie dog, Cynomys ludovicianus, is found in the Great Plains from extreme southern Canada south to the Mexican border, chiefly in the Upper Sonoran Life-zone but some colonies occur in the Lower Sonoran Life-zone and a few in the Transition Life-zone. See figure 1. A nominal species, Cynomys mexicanus, occurs in _ , x^. ., . r , , , , , ^ 1 .1 xt - Fig. 1. Distribution of the black- southeastem Coahuila, Mexico. tailed prairie dogs 9 — FOOD HABITS Kelso (1939) found that two-thirds to three-fourths of the food was grass. Plants unimportant as forage for livestock comprised about 23 per cent of the food. In general, my findings agreed with his. The overgrazed pasture where my study was made had as dom- inant grasses: Blue grama, buffalo grass, foxtail barley, and aris- tida (both Aristida Jongiseta and A. purpurascens) . Including annu- als, thirty-seven species of plants, as listed immediately below, were fairly common throughout the dogtown. Taxonomic Name Amaranthus graecizans Ambrosia psilostachya Andropogon saccharoides Argemone sp. Aristida longiseta Aristida purpurascens Asclepiodora decumbeus Asclepiodora viridis Baptisia leucophaea Baptisia minor Bouteloua gracilis Buchloe dactyloides Callirhoe alcaeoides Callirhoe involucrata Chloris verticillata C rot on texensis Euphorbia marginata Euphorbia serpens Evolvulus nuttallianus Froelichia ftoridana Gaura coccinea Geranium carolinianum Hordeum jubatum Lepidium densifiorum Lippa cuneifolia Muhlenbergia sp. Opuntia sp. Oxalis europaea Paspalum ciliatifolium Plantago Purshii Plantago virginica Proboscidea louisianica Schrankia uncinata Solanum rostratum Tradescantia ohiensis Verbena bracteasta Yeronia Bcldwini Vernacular Name white pigweed western ragweed silver beardgrass white prickly poppy red three-awn arrow feather milkweed green milkweed Plains wild indigo wild blue indigo blue grama buffalo grass light poppy mallow purple poppy mallow windmill grass Texas croton Snow-on-the-mountain Spurge Nuttall evolvulus Froelich amaranth scarlet butterfly weed Carolina geranium foxtail barley peppergrass frogfruit wirestem muhly cactus yellow wood sorrel paspalum wooly plantain Virginia plantain devil's claw sensitive briar cocklebur spiderwort prostrate vervain ironweed — 10 — In the later part of June, prairie dogs eat the seed-heads of foxtail barley, grama grass (both heads and leaves), buffalo grass, and cocklebur leaves. Milkweeds are cut but not eaten. All through the summer grasshoppers and a few other insects are eaten, always head first. In July, grama grass heads, foxtail heads, cocklebur leaves, and around the middle of the month buffalo grass stolons and aristida awns are consumed. In August, foods are buffalo grass stolons, grama grass, aristida awns and leaves, as well as cocklebur seeds that are shelled from the cockleburs, and seeds and leaves of various low-growing plants found on the mounds, particularly white pig weed, CaroHna gera- nium, spurge, and yellow wood-sorrel. In autumn and winter, dry buffalo grass, grama grass, and aris- tida grass comprise the main part of the diet. In December occa- sional clumps of cactus (Opuntia sp.) were eaten. In January, February, and March considerable digging for roots of grasses and forbs takes place (see plate 1, fig. 1). This was especially evident in the early months of 1957 when a prolonged dry spell and over- grazing had reduced the vegetational cover to almost nothing. Cer- tain areas, especially those supporting stands of Andropogon, were so dug up as to give the appearance of having been cultivated. Prairie dogs gathered from considerable distances at these places and dug small holes three-and-a-half to four inches in diameter and four to five inches deep. In April considerable quantities of the darkling beetle, Eleodes hispilahis, were found around the burrow openings and remains were found also in stomach contents. In the later part of April, May, and early June, peppergrass was consumed in considerable amounts; in some stomachs this annual made up fifty per cent of the contents. In mid-June of 1955, when my study was begun, grass covered thirty-five to forty per cent of the ground in the dogtown. The grass was cropped short within the dogtown, but was tall at the edge. This tall grass was grama having seed heads ten to fifteen inches high, foxtail barley having seed heads eight to ten inches high, and buffalo stolons eighteen to twenty-four inches long. Cattle, like other grazing animals, do not graze the range evenly but in "favored" places. The area of this prairie dog town is just such a favored (by cattle) area, as, indeed, are most of the prairie dog towns of Barber County. A windmill stands on the hill at the north edge of the dogtown and there is a pond formed by a dam at the southern edge of the town. Cattle gather at these places, mill- ing about, drinking, grazing, resting, and at the pond finding relief — 11 — from the flies by wading into the water. The combination of the 300 head of cattle and native rodents deleteriously affect vegetation and prevent the growth of grass. As the drouth continued in 1956, some areas of the dogtovm were bare and other areas were fifteen per cent covered by vegetation whereas outside the dogtown the vegetation covered twenty-five per cent of the ground. The pond dried up late in June and was completely dry for eight months. In the autumn the cattle were taken off the area. Severe dust storms occurred; wind eroded areas around the pond and windmill. In December of 1956, and in Janu- ary, February, and March of 1957, the prairie dogs dug for roots until parts of the dogtown looked as though they had been culti- vated. April and May brought ten inches of rain, which came in slow drizzles, soaking in with little or no runoff. Annuals, espe- cially peppergrass, began to green up the area and form a dense ground cover. How extensive the damage to the grass had been cannot be determined at this writing. Since the study by Taylor, Vorhies, and Lister on jackrabbits in 1935, the concept of "animal weeds" set forth by them has been ac- cepted by most ecologists. The concept is that certain animals, like certain plants, increase with the disturbance of the climax and de- cline as the climax is restored. Data in numerous papers have sub- stantiated the concept but it seems not to be fully understood by many farmers and ranchers, who could make the most use of it. Even the farmer-rancher group accepts the fact that rabbits and various range rodents are more numerous on depleted and weedy ranges than on ranges of good vegetative cover, but almost without exception wrongly regards these mammals as the "cause" instead of the "result" of range depletion by overgrazing. Taylor, Vorhies, and Lister set up protected plots next to plots heavily grazed by livestock and separated only by a barbwire stock- fence. Grazing pressure from jackrabbits was three times as heavy on the plot grazed by cattle as on the protected plot. At the Wichita Mountains Wildlife Refuge in Oklahoma, Osborn and Allan recorded an instance where a prairie dog colony was protected and cattle were removed from the area. In spite of the activities of the prairie dogs, the grass cover increased in density and the prairie dogs abandoned the area because it reverted to vegetation unsuitable as a habitat for them! These findings are supported by observations in Barber County. In 1946, Mr. Floyd T. Amsden acquired a 640-acre section across the road from the pasture in which the dogtown is situated but one mile south of the town. At that time Amsden's land was a badly — 12 — eroded, overgrazed area, resembling the rest of northeastern Barber County. From 1946 to 1956 Amsden's land was not grazed but was managed for the production of wildlife. Now (1957), the hills are covered with stands of sand bluestem (Andropogon hallii) four to six feet tall and the drouth has had little visible effect on the veg- etative cover. Jackrabbits, grasshoppers, and even the thirteen- lined ground squirrel are few compared with the populations just across the road. Since 1950, five different prairie dog towTis have been started in overgrazed pastures within a five mile radius of the main dogtown. Mr. Amsden, owner, and Mr. Crocker, game manager, of Plum Thicket Farm have reported three instances of finding prairie dogs on Plum Thicket Farm, but prairie dogs never establish colonies there. It is obvious from these studies that overgrazing by cattle is pri- marily responsible for the disappearance of the range grasses. Thus room is made for the annuals and their fleshy roots and larger and more numerous seeds, that constitute an increased food supply. Consequently the prairie dog population increases. In times of drought, prairie dogs may help cattle destroy the range completely. The remedy, of course, is to remove the cattle. Under ordinary conditions, however, herbivorous small mammals may speed up plant succession by their preferential food habits; they eat plant species typical of early successional stages — plants not eaten by cattle. J. R. Mead's observation in 1859, that ". . . the foot of the buffalo was necessary for their [prairie dogs'] existence" and that "As soon as . . . the grass and weeds grew they perished," holds true for the prairie dog-cattle relationship also. Proper man- agement of cattle is the keynote of success in reducing the numbers of prairie dogs on range land. BEHAVIOR Communication The alarm bark is given to indicate animals or objects not neces- sarily considered dangerous but irritating by their presence, such as a man, cattle, traps, instruments, and vehicles. The prairie dog runs to its mound and crouching over the burrow emits a two-syl- lable sound — tic-uhl; tic-uhl; tic-uhl — the first syllable of which is of a higher pitch and shorter duration than the second. The bark is accompanied by a vertical flick of the tail; frequently all that can be seen of the prairie dog is its head and tail. The frequency and intensity of this bark is greatest during the first two or three minutes in which it is given; thereafter the frequency slows to around forty — 13 — barks per minute (this varies considerably) and may continue for as long as an hour-and-a-half. On hearing this bark all prairie dogs in the immediate vicinity sit up and look around; if they too are suspicious of this object or animal they run to their mounds and join in the bark. Some prairie dogs, however, utter the alarm call so often that, as in the case of the alpine shepherd boy who called "wolf" too often, associates pay no attention. One old female in the area of blind No. 1 established the one-and-a-half hour record mentioned above. She could not induce the others to look up from their routine activities whenever she instituted the alarm bark. She barked at everything — horned larks, cattle, rabbits, large landlubber grasshoppers, and of course at me. The predator or hawk warning bark consists of the same two syl- lables as the alarm bark, but because the second syllable maintains a high pitch the two barks are recognizably different. Individuals do not wait to perceive the danger themselves, as with the alarm bark, but dash for their burrows. Prairie dogs reaching the safety of the burrow entrance may emit the typical alarm bark as long as the predator is near. This predator bark is given in response to soaring birds and the badger. Interestingly, a prairie dog will feed within fifteen to twenty feet of a vulture on the ground, but if the bird is flying and especially if the shadow of the soaring bird passes across the area, then the prairie dog perceives the bird as dangerous and emits the predator bark. A prairie falcon sitting on the ground does alarm the prairie dogs. One windy afternoon a prairie falcon alighted in the dogtown to rest and preen. Its presence evoked considerable commotion; prairie dogs watched it from their mounds and barked excitedly until the falcon left thirty-five minutes later. Badger activity within the dogtown could easily be pin-pointed in early morning or late evening hours by listening for this bark. An amusing call that is diflBcult to interpret without anthropomor- phizing a bit is the "all clear" call. When it is emitted the prairie dog always throws its forefeet high into the air and brings them down in the manner of a grand salaam — often with such force that the animal falls over backwards or leaps into the air. This also is a two syllable call — aeeee-ou — , the first syllable being uttered in a high pitch as the forefeet are thrown into the air, and the short, guttural, second syllable is omitted as the forefeet drop to tlie ground. This call is heard after danger is past and so is given the "all clear" interpretation, but is repeated again and again on warm, clear, sunny mornings just after the prairie dogs come out of their — 14 — burrows. At tliis time it is "contagious" and goes the rounds of all who are already out. During feeding in late morning this call may be given for no apparent reason, but at this time is not so "con- tagious" to others and therefore causes an observer to wonder if the call is a greeting. When my pet prairie dog was in the house or yard and did not come when I called, her whereabouts could be determined by my giving an admittedly poor imitation of this call, which was immediately answered by her in true prairie dog style. Certain prairie dogs seemed to be antagonistic towards thirteen- lined ground squirrels, and before giving chase emitted a low- pitched snarl. The sound was also heard from a few prairie dogs in the laboratory when they were handled. Tooth chattering consists of gnashing the teeth together rapidly, and is accompanied by occasional low, muffled barks. Animals in the laboratory frequently do this while asleep, and animals in the field have been observed "chattering" while being groomed by another prairie dog. One author had the idea that the chattering is a warning or indication of anger; my observations do not support this idea and suggest that the chattering has many meanings, and possibly sometimes none at all. A scream is emitted that seems to be a fear reaction. Young prairie dogs being handled for the first time occasionally give this scream; and I heard it one evening when a badger was chasing a prairie dog. The chase ended out of my sight behind an earthen dam. When the scream was given the other dogs watching the chase bolted down their burrows. Although the place was investi- gated as soon as I could get to it, the badger had disappeared into a hole and no sign of blood was found; therefore, it cannot be as- sumed that the scream was from a dying animal. Vocalizations associated with aggressive behavior and defense of territory have been reported by King (1955:73-76). On the Barber County study area in Kansas, aggressiveness and territorial disputes as described by King (loc. cit.) for prairie dogs in South Dakota, were so infrequent that I was unable to draw adequate con- clusions from them. Intraspecific Contacts The mouth contact or "kiss" is effected by one prairie dog turning its head slightly and touching its open mouth (incisors) to that of another prairie dog, after which they may graze together, groom each other, or go in opposite directions. The contact often occurs when a prairie dog is on its mound and another, or others, run to the mound; the first prairie dog "kisses" the others as they arrive. — 15 — When prairie dogs are grazing, one may run to another a few feet distant, "kiss," and return to grazing. In one stage of their develop- ment, young prairie dogs move about making mouth contact with every prairie dog that they see. Animals in the laboratory fre- quently behave as though they desired to "kiss." In such instances the desire seems to be satisfied if a person grasps their incisor teeth by means of his fingers. If a prairie dog in nature does not 'Tciss," the one making the advance frequently raises its tail, spreads it, and snarls; then either a "kiss" results or a chase is on. Sometimes, a crouching position is assumed by both prairie dogs. Then the first one turns around showing the three anal glands, which the other prairie dog smells. Then the position is reversed and the first prairie dog smells the other prairie dog's anal glands. After all this the two prairie dogs wander oflF to feed. Mouth contacts may or may not precede grooming (one prairie dog using its teeth to go over the fur of another). This activity is obviously more than just getting rid of external parasites, and prob- ably creates a pleasant tactile reaction as laboratory animals free of external parasites continue to groom each other. A pet prairie dog is fond of being scratched or even brushed, and in return "grooms" the hair on a person's arm or nibbles at the skin on the hand. In some animals, grooming is reported to occur according to a hierarchy, thus demonstrating a dominance of certain individuals by others. As for my observations, one animal did not groom any one more frequently than another. The young seem to be fond of being groomed and of grooming, and adults of both sexes indulge the young in this activity. Prairie dogs seem to enjoy being in close proximity to each other, this often being observed as they sun themselves or gather on the mound. Laboratory animals nestle or huddle together at night. Their sleeping positions are varied but two positions seem to be pre- ferred over others. The position most often observed is a sitting one with the forelegs crossed over the chest and the head bent down between the hind legs giving the appearance of a furry ball. An- other highly favored position consists of lying on the back, forelegs crossed over the chest or sometimes all legs relaxed with no definite position assumed and the head resting on the body of another prairie dog. Laboratory animals frequently bark in their sleep and on occasion it has been necessary to wake my pet prairie dog in order to quiet her. Since 1950, I've had three pet prairie dogs and each so barked. I have spent some time at night Hstening at burrows but without hearing any sound therefrom. — 16 — In early morning, on the sunny side of the mound, when the sun is just high enough to warm the mounds, a prairie dog frequently spends ten to twenty minutes stretched out on its belly, forelegs straight ahead, hind legs straight behind, sunning itself. This sun- ning is accompanied by much yawning and stretching but the posi- tion itself is not changed. Daily Routine and Feeding Behavior In July, prairie dogs are above ground by 5:30 A. M., but in Jan- uary, they rarely come above ground before 10 A. M. to 11 A. M. They spend 10 to 20 minutes after coming above ground sitting on the mound, looking around and greeting (kissing) other prairie dogs as they appear. The prairie dogs then move out to feed and after 30 minutes to an hour return to the mound to stretch out and sun themselves. After the initial feeding, especially in spring and summer, considerable play activity takes place among the young, and the young and the adults. In summer the heaviest concentration of feeding activity occurs from 7-11 A. M. and 5-8 P. M. Population counts are best made in these hours. They feed at all hours of the day, occasionally going into the burrows to rest, and frequently dashing to the mound in response to the alarm call of another prairie dog or spending 10-15 minutes ascertaining whether an alarm call in another part of the town should be responded to or not. Although prairie dogs wander in the course of feeding, characteristically an hour or two is spent eating buffalo grass stolons or foxtail barley heads, and another hour or two is spent eating grama grass or possibly cocklebur plants. In summer about one-third of the daylight hours are spent in actual feeding, one-third in wandering around, playing, working on mounds and burrows, or responding to alarm calls, and one-fourth to one- third of the daylight hours are spent in the burrow. At sunset, prairie dogs come in from the outlying areas and feed closer to the mound. They begin to enter the burrow one by one until 15-30 minutes later all are below ground and the dogtown is quiet. This complete silence impresses on an observer how noisy these gregarious creatures really are. In feeding, a prairie dog cuts vegetation at its base, stands up- right with the food in one paw and eats from the basal portion distally. In this way, spiny plants such as the cockelbur can be eaten without injury to the mouth. Frequently only a few bites are taken, the rest is discarded, and a new stalk of grass is cut. While feeding, the prairie dog waddles about in a leisurely manner, but if the predator call should be given, leisure gives way to haste. 17 — Relations to Weather and Seasonal Activity Humidity had no noticeable eflFect on the prairie dogs; of course during rains or snow storms the animals remained in the burrows. See plate 1, fig. 2. Wind velocity under thirty-five miles per hour had no noticeable ejffect. Winds of higher velocity almost all were the hot dry winds of July and August and it was difficult to single out either the heat or the high velocity of the wind as the cause of the prairie dogs remaining in their burrows. Prairie dogs like sunshine and warm weather, but, like many other animals, are unable to tolerate temperatures much higher than 100° F. In June, July, and August of 1955, there were 23 days of 100° F. readings or higher. In July and August of 1956, there were 18 consecutive days of temperatures higher than 100° F. — the high- est was 112° F. In these periods the prairie dogs showed no inclination to aestivate but concentrated their feeding and above- ground activities in the early morning (5:30-9:00 A.M.) and late evening (6-8 P. M.). Prairie dogs were out at all hours of the day but for only a few minutes at a time; then they returned to the comparative coolness of the burrows. On mild days the tempera- ture in the burrow five feet below the surface was 74° F., on the hottest day it was 76° F. at the same level. During the summers of 1955 and 1956, five dogs died in live traps from the heat, even though the traps were checked every three hours. Overheated prairie dogs foam at the mouth; their faces, throats, and chests become wet with saliva. In August, 1956, after three days of 108° F. temperatures, fifteen animals in cages in a building died of the heat and ten others were revived by immersing them in buckets of water. These laboratory caged animals were kept in a cement washhouse, shaded by trees, with good ventilation, and were supplied with drinking water. Light intensity also affects prairie dogs by increasing their activity. The most noticeable effect concerns their entrance into the burrows at night. In winter (January), prairie dogs retire for the night at about 4:00 P. M. In summer (July) they retire around 8:00 P. M. In summer they retire 15 to 30 minutes after sunset; in winter the intensity of the sun's rays begins to wane considerably before it finally sets. As a result, things begin to "cool off" rapidly and the prairie dogs retire about an hour before sunset. Several times I have released prairie dogs from traps about an hour after sunset (still light enough for me to see clearly) and have watched the prairie dogs groping blindly for the mound and then for the entrance. They not only bump into objects but also fail — 18 — to show fright or alarm, and can be picked up or touched without making their usual defensive reactions. Relations to Associated Animals As a rule all animals associated with the prairie dog and not con- sidered predators are tolerated or ignored. Meadowlarks, lark buntings, and killdeer were abundant around the pond and in the dogtown, where they nested and secured their food. It was not uncommon to observe 7-8 meadowlarks and 7-8 killdeer feeding in a group of 10-12 prairie dogs. The birds flew back and forth over the prairie dogs, walked all around them and in all my observations were totally ignored by the prairie dogs. Burrowing owls, although not abundant, were present and caused an occasional prairie dog to sit up and watch but never caused an alarm call to be given. Rabbits, both cottontail and jackrabbit, were abundant. Cotton- tail rabbits were often observed coming out of prairie dog burrows or crouching just inside. Many were caught in live traps, espe- cially at night. They never caused the alarm bark and now and then were approached by a prairie dog, sniffed and ignored. Neither appeared afraid of the other. Jackrabbits were even more abundant than cottontails and when quietly feeding caused no alarm, but often they would take off on a fast sprint or even a gentle loping gait which caused the prairie dogs to dash for their mounds from which vantage point they watched the jackrabbit disappear. In early morning six to ten jackrabbits would congregate at various seem- ingly established places near the edges of the dogtown and engage in a sort of play activity; while four to eight rabbits sat in a circle, two others would run around this circle, one following the other by about ten feet, and these two would "take their places" in the circle and two others would take off. All the while guttural sounds would be audible from the group of rabbits. During such activity, prairie dogs would sit on their mounds and watch. This happened two to three times a week in summer and the prairie dogs seemingly always remained curious about it, just as I did. Three species of lizards, Holbrookia maculata, Sceloporus undu- latus, and Phrynosoma cornutum were present in the dogtown and were found in the burrows as well as above ground. The prairie dogs seemingly paid no attention to them. Three times the toad Bufo cognatus was found in burrows but was never observed out away from the mounds. By far the most abundant reptile was the ornate box turtle, Ter- rapene ornata. It was not at all unusual to have 6-8 feeding or moving about in the area of blind No. 1 in early morning or late — 19 — evening. Mostly the box turtles were ignored by the prairie dogs but on occasion they exhibited considerable curiosity concerning the turtles' actions. As a box turtle would crawl under a cow-chip and start to raise it up so it could be turned over, the prairie dog would sit up and watch until the chip was successfully up-ended and then would return to its feeding. In one instance a prairie dog was seen to approach a box turtle and make a jump at it as prairie dogs do when they play. Of course the box turtle retreated into its shell, but after a few seconds re- appeared and snapped at the prairie dog. This ended the encounter, and the prairie dog went oflF to feed. Ornate box turtles use prairie dog burrows for refuges and hibernate in them. Mostly old burrows of the slanting type are used, but three or more times in spring, in as many burrows, I have looked into a burrow that went straight down for six to eight feet and with the aid of a flashlight observed an ornate box turtle vainly trying to leave a burrow much too wide for the turtle to climb. Of snakes, only four individuals were detected in the dogtown in the two and a half years of field study. They were a western hog-nose snake, Heterodon nasicus; a massasauga, Sistrurus catena- tus; a lined snake, Tropidoclonion lineatum; and a bull snake, Pitu- ophis melanoleucus. Of these only the bull snake could be con- sidered a predator on prairie dogs. Only one individual of the bull snake was ever seen there and it was taken from an abandoned burrow. Indeed, it was in a small area long abandoned by prairie dogs and where considerable numbers of Perognathus and Peromys- cus were trapped. Thirteen-lined ground squirrels were abundant, and in summer ran in and out of old prairie dog burrows although these squirrels dug their own hibernating burrows. In a few instances prairie dogs seemed to ignore ground squirrels but in most cases the prairie dogs reacted positively to a ground squirrel in sight. Upon seeing the ground squirrel, the prairie dog would utter deep throaty or guttural growls and chase the ground squirrel until it found shelter in a burrow. I never saw a prairie dog catch a ground squirrel and have no information as to what would happen if one were caught. OnycJwmys leucogaster, Perognathus hispidus, and Peromyscus maniculatus were taken within the dogtown. These inhabit old or little used prairie dog burrows. In winter a prairie dog burrow in- habited by Onychomys is readily noticeable because the entrance to the burrow is stuffed with dry grass except for a hole about the size of a half dollar. The reactions of the prairie dog to these 20 PLATE 1 ' »<*: '-.»>- ■&><'! •I^R' #1 ' .' m '^'% ' t ." \. Fig. 1. Holes dug by prairie clogs in search of roots. Fig. 2. Prairie dog tracks in snow. Prairie dogs in southern Kansas do not hibernate and in winter remain in their burrows only during storms. PLATE 2 Fig. 1. Remains of four prairie dogs killed by a badger. ^ jy^''%i^\ : >- -? ^' >. -VV .'• ;: n'l L li i s 5 ?-n ijSH M C > o «5 C/) 4^ • •^ Q 3 O u ;o c in e« 05 c 1—1 Ml n C ^ T3 > C O 0) HD & (U rt li K rt -c li j: o o :f ^ ^ W c c CTJ V3 c aj C8 frt UH T3 c 4-* e ^^ c 3 O o trt ^ o J3 (O bO c 'V rt _C C/J 05 6 — 32 — SUMMARY 1. Prairie dogs were studied from June of 1955 to June of 1957 in Barber County in one of the last large (115 acres) prairie dog towns in Kansas by means of observation and live trapping, supplemented by laboratory investigations. 2. Prairie dogs in Kansas inhabit the dry, upland pastures west of the 98th meridian. Only the species Cynomys ludovicianus (subspecies ludovicianus) is found in Kansas. 3. Prairie dogs are diurnal and in summer spend one-third of the daylight hours feeding; one-third playing, working on mounds and burrows, and responding to alarm calls; and one-third, presumably resting, in the burrow. 4. Prairie dogs are gregarious. No social hierarchy was detected. Territories exist but there is no aggressive action in defense of the territory so long as there is adequate food and/or room for expansion of the colony. 5. Communication within the dogtown consists of the alarm bark, the predatory bark, the "all clear" call, a snarl, tooth chattering, and a fear scream. 6. Intraspecific contacts among prairie dogs are on the whole friendly and include mouth contacts, anal recognition, hud- dling, grooming, and feeding. 7. Grass is the principal food of prairie dogs, but twenty-three per cent of their food is vegetation not eaten by livestock. Therefore, under ordinary conditions they exert a beneficial influence on the range by their preferential food habits. 8. In summer, prairie dogs are up at sunrise; the heaviest con- centration of feeding activity occurs from 7 to 11 A. M. and 5 to 8 P. M. They retire to their burrows within thirty minutes after sunset. In winter, prairie dogs may not come above ground before 10 A. M. and retire by 4 P. M. Most of the above-ground activity in winter is concerned with feeding. 9. In feeding, the prairie dog cuts vegetation at its base, and holding the food in one paw eats from the basal portion distally. In this way spiny plants can be eaten without injury. 10. Changes in humidity (short of actual precipitation), in wind velocity, or in barometric pressure seem not appreciably to influence prairie dog activity. However, temperatures below freezing restrict their activity as do temperatures higher than 100" F. Light intensity influences their activity, and in the — 33 — absence of sufficient intensity they seem to be blind; they bump into objects and fail to show fright or alarm. 11. As a rule, animals that do not prey on the prairie dogs, are tolerated and ignored. The one exception is the thirteen-lined ground squirrel; its presence evokes throaty growls and aggres- sive action in the form of a chase from the prairie dog. 12. The badger, a carnivore, was the only animal found preying on prairie dogs in Barber County. Hawks and bull snakes may take the young in June and July. 13. Permanent burrows are dug in spring or autumn. The open- ings tend to be in the direction of downward slope. Certain permanent burrows give an element of stability to the dogtown, as from these, repeated "assaults" are made on the peripheral areas of the dogtown. Burrows vary in depth and length of underground tunnels according to type of soil, and terrain. 14. Mounds vary in height from a foot to three feet, and in width from three feet to ten feet. Ninety per cent of the mounds are loose earth thrown out in a pile. Mounds of the dome type are constructed when the soil is moist, and are packed by forcefully driving the nose into this material. Dome type mounds are formed by scraping up soil and grass from the sur- rounding area as the burrow itself has been dug from the bottom up. 15. A spring molt occurs in the last of April and begins around the ears, eyes, nose, and under the chin. New fur appears on all the toes and on females around the nipples and genitalia, and in males in the midline down the ventral region and spreads outward toward the axillary regions. These areas all become connected and the acquisition of new fur continues poste- riorly; the pelage of the tail is the last to change. An autumnal molt occurs in October, and is characterized by a thicker, longer, more buff-colored fur. 16. The breeding season begins around the last of January and lasts for two to three weeks. The gestation period is 30 to 32 days. The average litter is four. 17. The Barber County prairie dog town increased by twenty-five acres in four years and is at least thirty years old. 18. Under vmsuitable conditions prairie dogs emigrate (usually in pairs) to more favorable areas, generally within a five mile radius of the old dogtown. 19. Dense vegetation is a limiting factor in the establishment of new dogtowns. Since overgrazing of the range by cattle or — 34 — bison is necessary before the prairie dog can successfully establish itself, one of the most successful methods of con- trolling prairie dogs is to remove the cattle from the range until it has had a chance to recover. Prairie dogs are the "result" of range depletion by overgrazing by cattle. 20. Because of their gregariousness prairie dogs are easily poisoned and w^hole towns are thus completely destroyed. In the last 52 years almost 2,442,955 acres of prairie dog towns have been destroyed in Kansas. Less than 57,045 acres of prairie dog towns remain in the state and 20,000 of these acres are sched- uled for poisoning by the end of this year ( 1957 ) . In 1947, Theo. H. Scheffer wrote: "Man's primaeval claim to dominate all animal life did not contemplate the destruction of a race. . . . All creatures of the wild have had, or still have a certain value to us in the niche they fill. It goes with- out least argument that these niches must be narrowed as we encroach upon them with our essential occupations of life; but there always has been, always will be space for the survival of the lowly." To this may I add my plea — that the farmer-rancher think of control of these animals instead of their total destruction. He has a two-fold obligation in this connection to his progeny; 1 ) leave his land in better condition than when he received it; 2) retain the aesthetic value inherent in the native plants and animals on that land. Proper management of cattle will insure a good cover of grass that is of monetary value to the farmer, will fulfill his obligation to his progeny, and will control num- bers of the prairie dog without annihilating the species. LITERATURE CITED Allen, J. A. 1877. Scitiridae, pp. 631-940, in Coues and Allen, Monographs of North American Rodentia, Rept. U. S. Geol. Surv. Territories, ll:xii -|- x -f- 1091, 6 pis. Anthony, A,, and Foreman, D. 1951. Observations on the reproductive cycle of the black -tailed prairie- dog {Cynomys ludovicianus). Physiol. Zool., 24:242-248. Baird, S. F. 1858. Explorations and surveys for a railroad route from the Mississippi River to the Pacific Ocean. War Department. Mammals, 8( 1) :xlviii -f 757, pis. 17-60. HOLLISTER, N. 1916. A systematic account of the prairie-dogs. N. Amer. Fauna, 40-1-37, 7 pis., 2 figs. — 35 Kelso, L. H. 1939. Food habits of prairie dogs. U. S. Dept. Agric. Circ, 529: 1-15. King, J. A. 1955. Social behavior, social organization, and population dynamics in a black-tailed prairiedog town in the Black Hills of South Dakota. Contrib. Lab. Vert. Biol, Univ. of Michigan, 67:1-123, 4 pis., 11 figs. OsBOBN, B., and Allan, P. F. 1949. Vegetation of an abandoned prairie-dog town in tall grass prairie. Ecology, 30(3):322-332, 4 figs. Mead, J. R. 1899. Some natural history notes of 1859. Trans. Kansas Acad. Sci., 16:280-281. Merriam, C. H. 1901. The pMiirie dog of the Great Plains. U. S. Dept. Agric. Yearbook, 1901:257-270, pis. 22-24, 1 fig. Lantz, D. E. 1903. Destroying prairie-dogs and pocket-gophers. Kansas State Agric. CoU. Exp. Stat. Bull., 116:147-163. SCHEFFER, T. H. 1937. Study of a small prairie-dog town. Trans. Kansas Acad. Sci., 40:391-394, 1 pi. 1947. Ecological comparisons of the plains prairie-dog and the Zuni species. Trans. Kansas Acad. Sci., 49(4):401-406. Seton, E. T. 1926. The prairie-dogs (Cynomys ZudotJtciantw) at Washington Zoo. Jour. Mamm., 7(3):229-230. 1929. Lives of game animals. . . . 4:xxii + 949 pp., illustrated. Doubleday, Doran & Co., Inc., Garden City, New York. Sperry, C. C. 1941. Food habits of the coyote. U. S. Dept. Int., Fish and Wildhfe Service, Wildlife Research Bull., 4:i-vi + 1-70, colored frontispiece -f pis. 2-3, 3 figs. Taylor, W. P., Vorhies, C. T., and Lister, P. B. 1935. The relation of jack rabbits to grazing in southern Arizona. Jour. Forestry, 33 ( 5 ) :490-498. Tfonsmitted December 26, 1957. D 27-2178 Addenda 00 o o- i o o o z >. o r •I 3 3 2 0» o o ?-n 8- — 38 Addenda, in 1967 After this bulletin was printed in 1958, requests for copies exhausted the supply much sooner than was expected. Continuing demand for copies is responsible for reissuance of the bulletin at this time. Figure 9 on page 32 of the 1958 bulletin showed only counties at that time reported to have at least one town of as much as 40 acres. The shading on Figure 10 on page 38 shows counties reported by county agricultural agents, or as observed by me, to have prairie dog towns in 1967 (irrespective of size). The eastern margin of the geographic range of the prairie dog in Kansas in the spring of 1967 is regarded as accurately shown in Figure 10. The dog town of 115 acres jn Barber county described in detail in this publication was revisited on April 8 and 9, 1967, and studied by Ronald E. Smith along with Stephen R. Wylie. In ten years, the town had expanded eastward 150 fect in a strip about 300 feet long from north to south and the prairie dogs had withdrawn from an area of corresponding size on the northwestern part of the dog town. The total area of the town is about the same in 1967 as it was 10 years before but the number of prairie dogs was fewer — about 1,408 instead of about 2,300 in 1957. In early June after the young are in evidence the population would be about 3,408 in 1967 instead of about 4,000 as it was in 1957. The area is reported to have been heavily grazed every year since 1957 but seems to have been less heavily grazed in the three or four years just passed than in the preceding six or seven years. For a few years after this publication was issued, efforts to decrease the numbers of prairie dogs may have declined, and their nvmnbers may have increased. Many ranchers now are attempting to reduce or extirpate prairie dogs from their lands. Where artificial reduction in size of a prairie dog town by means of toxi- cants is undertaken, the Kansas State University rodent control expert in 1967 recommends the use of chlorofume. It is outstandingly effective when used according to directions but like any toxic gas has the disadvantage of kiUing all animal life in the burrows treated. After examining my data on numbers and distribution of prairie dogs in Kansas in 1967, Professor Ronald E. Smith {in Litt.) observes: "Ten years ago my Cassandra-like prophecy for these animals was most pessimistic. Now I see a ray of hope, not that these animals will increase in number, but at least for the survival of the small population that is left. The willingness of farmers and ranchers to recognize the dangerous plight of these animals, to recognize that their presence is not the cause but only the result of over- grazing, to recognize that effective control lies in good ranching practices and not in mass poisoning programs, and their attitude of protecting our dwindling wildlife and its habitat for future generations give me hope and confidence in the survival of the prairie dog." — Stephen R. Wylie. Transmitted June 9, 1967. — 39 — 3 2044 093 361 590 Date Due