UNIVERSITY OF KANSAS PUBLICATIONSMUSEUM OF NATURAL HISTORY Vol. 10, No. 7, pp. 553-572, 4 pls. , 3 figs. May 4, 1959 Home Range and Movementsof the Eastern Cottontail in Kansas By DONALD W. JANES UNIVERSITY OF KANSASLawrence1959 UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Robert W. Wilson Volume 10, No. 7, pp. 553-572, 4 pls. , 3 figs. Published May 4, 1959 UNIVERSITY OF KANSASLawrence, Kansas PRINTED INTHE STATE PRINTING PLANTTOPEKA, KANSAS1959 Home Range and Movementsof the Eastern Cottontail in Kansas By DONALD W. JANES INTRODUCTION A knowledge of the home range and movements of the cottontail(_Sylvilagus floridanus_) is one of the most important prerequisitesfor estimating effectively its numbers and managing its populations. Bycomparing results obtained from different methods, previously used, fordetermining the size of the home range I have attempted to develop amore valid procedure. The study here reported upon was made on the University of KansasNatural History Reservation (Sec. 4, T. 12S, R. 20E), thenortheasternmost section of Douglas County, Kansas, approximately 6-1/2miles north-northeast of the University campus at Lawrence. The590-acre reservation, situated in the ecotone between the easterndeciduous forests and the prairie of the Great Plains near the northedge of the Kansas River Valley, has been protected as a "natural area"since 1948 (Fitch, 1952). It consists of tree-covered slopes, and flatgrass-covered hilltops and valleys. Two limestone outcrops follow thecontours about five and 20 feet below the tops of the hills. The 90-acre study area consists of a valley bordered on the north by awooded slope and on the southeast by another wooded slope adjacent to anarrow hilltop, east of which is another wooded slope. The area is thusan alternating series of three wooded slopes and two grass-covered, relatively level areas. The wooded slopes rise from the valley for about 125 feet at a grade ofapproximately 16 per cent. There is a sharp increase in grade to 36 percent 100 feet below the top of the hills. A natural terrace 50 feet to100 feet wide parallels the hilltop at the base of the 36 per centincline. The vegetation of the northwest-facing wooded slopes has been describedby Packard (1956). It consists of American elm (_Ulmus americana_), shagbark hickory (_Carya ovata_), chestnut oak (_Quercusmuehlenbergii_), black oak (_Quercus velutina_), and black walnut(_Juglans nigra_), in that order of dominance. Honey locust (_Gleditsiatriacanthos_) and hackberry (_Celtis occidentalis_) are also present. Shrubs and herbs of the lower story include greenbriar (_Smilaxhispida_), wild grape (_Vitis vulpina_), Virginia creeper(_Parthenocissus quinquefolia_), coralberry (_Symphoricarposorbiculatus_), gooseberry (_Ribes missouriense_), bluegrass (_Poapratensis_), sedges (_Carex_ sp. ), poison ivy (_Rhus radicans_), andwhite snakeroot (_Eupatorium rugosum_). The flat hilltops are covered by a mixture of grasses and forbs but aredominated by awnless brome (_Bromus inermis_). Foxtail (_Setariaglauca_), false redtop (_Triodia flava_), and panic grass (_Panicumclandestinum_) also occur commonly. Awnless brome is dominant in thevalley (Pl. 46, fig. 1; Pl 47, fig. 2) except in the eastern end wherebluegrass is dominant (Pl. 45). Near the tops and bottoms of the slopes barbed wire fences separate thewoodlands from the grasslands, which were grazed until 1948. Theborderline between woods and grasslands is well defined but woodyplants are rapidly encroaching into the grasslands. Young Osage orange(_Maclura pomifera_), American elm, and hackberry are common treesencroaching on the grasslands. The edge vegetation between woods andfields (Pls. 45 and 47) includes smooth sumac (_Rhus glabra_), coralberry and wild plum (_Prunus americana_). The lowland edges arecharacterized by blackberry (_Rubus argutus_), greenbriar andelderberry (_Sambucus canadensis_). Plates 45, 46 and 47 all show localhabitat in situations where traps were actually operated. Fitch(1952:8-22), Leonard and Goble (1952:1015-1026) and Martin(1956:366-372) have described parts of the Reservation that include thestudy area. I am grateful to Professor Henry S. Fitch for guiding my work, toProfessor Rollin H. Baker for suggestions and encouragement in theearly part of the study, to Mr. Robert L. Packard for certain trappingrecords that supplemented my own, and to Professor E. Raymond Hall forvaluable suggestions. Norma L. Janes, my wife, typed the manuscript. Photographs were taken by me. The State Biological Survey of Kansasprovided funds, equipment, and transportation. METHODS AND TECHNIQUES Schwartz (1941), Dalke and Sime (1938), Dalke (1937 and 1942), Hendrickson (1936), and Allen (1939) estimated the home range of thecottontail by drawing, on a map, straight lines that connected allmarginal points of capture in live-traps. The resulting home rangeswere polygonal figures. Haugen (1942) altered this method by drawinglines that connected points midway between the actual points of captureand the next outermost traps in the grid. Fitch (1947) used a methodfor enclosing all points of capture in a circle or ellipse thatrepresented the home range boundaries and expressed home range as thediameter of these figures. Another method, which has been used todetermine the home range of birds, is to map the movements of anindividual as it is observed. Stebler (1939) suggested the use oftracking records to determine home range. Connell (1954) expressed homerange of cottontails as the average distance traveled from a computedcenter of activity. The method was originally proposed by Hayne (1949). The methods used by other investigators to calculate the home range ofthe cottontail have yielded estimates varying from 0. 1 acre to 100acres. Such wide variations in the estimated size of home range mayresult from the use of different methods and from insufficient data. The data obtained from live-trapping are not fully adequate becausetraps cannot sample, in time and space, the entire home range of anindividual. Also, "trap habit" or "trap shyness" may distort theapparent shape of the home range. In order to compare these methods Ihave calculated home range from my data by each of five differentmethods. The results are shown in Table 1. No two methods yielded exactly the same results. To utilize allavailable data for each individual, I recorded on a map the locationsof capture in live-traps, nests and forms, locations where the animalwas observed in the field and the routes that it took between them. Atthe end of the study a line was drawn on the map to enclose the areaswhere the cottontail was known to have been. Live-traps were operated intermittently at 130 stations betweenDecember 8, 1954, and February 10, 1956. Sixteen cottontails weremarked in the same area by Robert L. Packard in 1954. Data from 7850trap nights were used in this study. The traps were set at fifty-footintervals and the pattern approximated that of a grid in habitatfavorable for cottontails such as at edges of woodland. In wooded areastraps were placed at fifty-foot intervals parallel to the edges. Trapswere not set on areas of poor habitat where neither cottontails northeir sign were observed. The traps were operated eight to twelve days and closed for two to fivedays intermittently throughout the trapping period except in the monthsof April to August, 1955, when trapping was unsuccessful because thecottontails then were not attracted by bait. Two kinds of traps were used in my study: those made by the NationalLive Trap Company and those described by Fitch (1950). Both typesperformed well and were serviceable under ordinary field conditions. Experiments were made periodically throughout the trapping period todetermine which bait was most attractive to cottontails and leastattractive to birds, rodents, skunks, raccoons, and opossums. All ofthese animals hindered operations by stealing bait and springing traps. Corn, scratch-feed, carrots, parsnips, tomatoes, lettuce, apple, cabbage, raisins, sorghum, sugar candy, and onions were used as bait. Corn and scratch-feed attracted cottontails best in all seasons. Cornwas superior to scratch-feed, which was quickly stolen by small birdsand rodents. Eighty-nine cottontails (40 females, 49 males) werecaptured in the course of the study. Cottontails were marked individually at the time of first capture. Whennecessary, the markings were renewed at later captures; in all suchinstances the same color codes and numbers were retained for each. Markings were of four types: numbered ear tags, colored ear ribbons, colored tail fur, and colored feet. It was intended to make eachindividual cottontail recognizable in a trap or in the field. Occasionally when a predator had killed and eaten a cottontail the tailand feet remained and, when dyed, they provided important clues to theidentity of the individual. However, the color of the feet is notordinarily discernible in the field while the rabbit is alive. Monel metal ear tags (size No. 4, National Band and Tag Co. ) werepunched through the lateral or posterior fold of the ear close to itsbase (Pl. 48), one in each ear as insurance against possible losses. However, only three tags were pulled out of the ears and lost in thecourse of this study. In no instance was identity of an individualcottontail lost. The tags caused no damage to the ears over a period of21 months. Trailing in snow is an effective method of studying the dailyactivities. The record preserved by the tracks becomes somewhatconfused after the snow has lain on the ground for more than one night, and after the third night it is impossible to read the surface of thesnow. The first day of thaw usually ends tracking because theinvestigator loses the trail when it crosses a patch of bare ground. The use of a dye on the feet of the individual to be trailed eliminatesmuch of the difficulty of determining which tracks are to be followed. One or more feet can be dyed when the investigator handles the animalin releasing it from the trap. The trail of dyed footprints isdistinguishable from all other rabbit tracks in the area. Even whenonly patches of snow remain, the animal can be followed by checking theedges of the snow for the emerging footprints of the marked rabbit. Thesame dye is used to color the tails. The color persists in thefootprints for about three hours, over a distance of 600 to 800 yards. The animal leaves only a small spot in each footprint, but when itpauses, the mark is large. Red dye makes the most conspicuous mark inthe snow. Thirty-one rabbits were trailed 68 times with one to six records fordifferent individuals. Almost two-thirds of the trailing recordspertain to males, which were caught more easily than females while snowwas on the ground. The trail, for both sexes, in those individuals released and followedimmediately was longer than in individuals released and allowed to moveaway before they were followed. The area ranged over by a trailedindividual was not significantly greater in either case. The arearanged over was greater by day than by night. Individuals continued tomove while being followed in the day, but stopped to forage and lookabout at night. Records were obtained by identifying cottontails that I flushed fromforms as I walked through the study area, sometimes using anoise-making device or dragging a rope. Regular search was made alongthe hilltop rock outcrops, under which hiding cottontails could beidentified with the aid of a flashlight. Forms in brush piles, andthickets were visited and the inhabitants identified. Other persons, working on the study area, supplied some of the records of cottontailsthat were seen alive or found dead. Also through binoculars or atelescope I watched movements of undisturbed individuals. Twenty-threeindividuals were identified 59 times. Nine females were seen 28 timesand 14 males were seen 31 times. Sixty-five other individuals wereseen, but could not be identified in the field. MOTIVATION AND EXTENT OF MOVEMENTS The home range is an area in which an animal carries on its normalactivities of eating, resting, mating, caring for young, and escapingfrom predators. The cottontail establishes a definite home range andmay live its entire life within this area, which permits familiaritywith food sources, hiding places, and escape routes. The cottontail usually establishes its home range in the area where itwas born, being semi-gregarious and tolerant of crowding. Eightcottontails that were captured and marked as young remained in the areaof original capture after becoming adults. Two of them lived 17 monthsin the same area, two lived 14 months, two lived 13 months, one lived12 months and one lived eight months. No young were observed to havemoved to another home range after they matured, although some may havemoved off the study area and thereby escaped observation. Young become independent and are seen foraging and moving about by thetime they weigh 200 to 300 grams, at an age of four to six weeks. Theyassociate with other young of the same litter and neighboring litters, and frequently frolic together. When two to three months old andweighing 400 to 700 grams they begin to live a more solitary life andusually rest alone in forms. Fourteen young between one and six weeksof age never were recorded to have moved more than 150 feet. The population reaches its peak in August or September; home rangesvarying in size from one-half acre (in young ranging in size from 150grams to 800 grams) to 12 acres, in adults, are superimposed upon eachother. In a woodland area of approximately 21 acres 33 cottontails wereliving together in September, 1955. As the growing season ends and winter approaches, the amount of foodavailable to the cottontail decreases and the cover becomes sparser(Pls. 45 and 46); predators, disease, and weather take their toll ofthe young. The survivors must move farther to find adequate food andcover. The home range of the cottontail in the first winter isoverlapped by the home ranges of the other members of the same litter, and members of other litters, as the home range is enlarged toapproximately its full size. By April the population reached its annuallow point; nine of the original 33 cottontails were known to havesurvived on the 21-acre area of northwest-facing wooded slope south ofthe pond. Foremost among the needs of the cottontail are food and cover. Dailymovements motivated by these needs are the most frequent and mostextensive that it makes. Movements such as are associated with courtingand mating, escaping severe weather, escaping from predators, andcaring for young are seasonal or irregular in occurrence. Because the abundant vegetation of summer provides adequate food andcover, movements made while foraging and seeking concealment are lessextensive than those made in winter when leafy vegetation is absent andfood is scarce. The average length of trails of foraging cottontailswas 175 feet per day in summer (11 individuals observed withoutdisturbance) and 325 feet per day in winter (22 individuals trailed orobserved without disturbance). In the spring and summer cottontails forage mostly near woodland edgesfor grass and herbs, and usually wander no more than 40 feet into thegrasslands from the protection of woodland edges and thickets. Inautumn and winter cottontails forage in woods and along woodland edgesfor bark of trees and shrubs and for fallen fruits of trees. Ninety-twoper cent of all fecal pellets found in grassland were within 40 feet ofcover suitable for cottontails. Movements made by the cottontail while foraging appear aimless; typicalbehavior consists of progression with a hesitant gait of two or threehops, a stop to eat, another series of hops and another stop. Footprints made by this movement are about 12 inches apart. Withoccasional spurts of hopping the individual moves perhaps ten to twelvefeet where it stops and begins to eat again. The area in which theindividual forages is usually elongated with its long axis parallel tothe edge except in areas of uniform habitat (such as large patches ofcoralberry) where the area covered tends to be more nearly circular. Cottontails observed foraging were estimated to utilize 10 to 20 percent of the home range area in one evening. Paths or runways are notordinarily utilized by foraging cottontails. In seeking protection from predators or from the weather, cottontailsmove farther in winter than in summer. The average length of trails ofcottontails flushed by me in the study area was 80 feet in summer and210 feet in winter. When cottontails were released from live-traps they ran an average of30 feet before stopping to look about. Cottontails always ran towardthe densest cover within 50 feet of the point of release. Ten per centof the cottontails released from live-traps did not stop running untilout of sight (always more than 30 feet). Movements made by cottontails escaping from predators differ frommovements made while foraging. The gait is a full run, often eight toten feet between footprints in snow; the trail is either straight orslightly zig-zag. If possible, the individual will take refuge in ahiding place such as a rock outcrop, brush pile, or thicket. Eightcottontails emerged from such hiding places an average of 22 minutesafter the disturbance ceased. If unable to find a hiding place a pursued cottontail will run 600 to1200 feet while circling and returning to the area from which it ran. If not closely pursued, it will usually (in 68 per cent of theinstances) not enter hiding places, but continue to run ahead of thepursuer. Of 70 released from live-traps and followed, 23 sought refugein hiding places. The others ran slowly (4 to 7 feet between footprintsin the snow) with frequent pauses to look and listen; they usuallysucceeded in keeping out of my sight. Twelve times the trails ofcottontails followed in this manner passed near a form, or otherresting place; always the cottontails had paused at the resting place, and twice the individual went into the resting place and ran out againwhen I approached. Resulting trails were almost circular, covering most(70-90 per cent) of the home range; sometimes three or four completecircuits were made. The trails made when I pursued cottontails rangedin length from 800 to 3, 000 feet. A trail recorded for an individual onone night was almost identical with another trail for the sameindividual recorded another night. The cottontail is not easily drivenout of its home range. Paths or runways are used by cottontailsescaping from predators in dense vegetation along fence lines, inthickets, or brush piles, or in snow that is eight or more inches deep. Most of the year cottontails rest in forms of grass or brush nearwoodland edges but in extremely cold or hot weather they seek thegreater protection of the woods. Movements are limited to the woodlandsin severe weather, especially when deep snow makes travel difficult. Hilltop rock outcrops on the area provide excellent protection for thecottontail especially from low temperatures and freezing rain orblowing snow. Eighty per cent of the cottontails resting under the rockoutcrops were found in severe winter weather. Fifteen per cent werefound in severe summer weather, and five per cent were found at timeswhen the weather was not severe. Undercut creek banks and exposed treeroot-systems in eroded gullies were favorite hiding places. Brush thathad accumulated in the ravines and stream beds also was used for coverby the cottontail. In heavy rain a cottontail may move along, neither hopping nor running, with its body close to the ground, head low, ears laid back. Losing itscustomary alertness it may pass a person without seeing him. At times, I have been able to approach almost close enough to seize one of themiserable creatures. In deep snow cottontails may progress with longbounds carrying them high enough vertically, to clear the surroundingsnow. Courting activities were seen only in evening. Four male cottontailsand three females were observed to move an estimated 1200 feet in anevening (1-1/4 hours) while chasing each other around in an area ofless than an acre. It is presumed that this activity was in addition tonormal movements made while foraging. Seven females known to be pregnant or lactating were not observed tomove more than 100 feet away from their centers of activity. Theirnests were never found. At the same time the males were moving overmuch larger areas. The cottontail is most active in the evening or early morning. Of thosefor which time of capture in live-traps was known 70 per cent werecaptured in the evening between dusk and 11:00 P. M. , 10 per cent werecaptured between 11:00 P. M. And dawn, and 20 per cent were capturedafter dawn. Nocturnal rodents and carnivores often stole bait in thenight; the percentage of capture of cottontails after dawn might havebeen larger had bait remained in all the traps. Except for those flushed, cottontails were seldom seen by day. In walksthrough the study area approximately three times as many cottontailswere flushed at night as in the daytime. On cloudy days cottontailswere active longer than on bright days. On dark nights more cottontailswere captured in live-traps between 11:00 P. M. And dawn than on brightmoonlight nights. Cottontails were more active (as determined by trap success andfrequency of observation) at temperatures between 0° F. And 33° F. Thanat temperatures between 33° F. And 55° F. Activity of the cottontailincreased as the temperature of the air decreased. Activity increasedin proportion to the percentage of ground covered by snow. Activity ofthe cottontail decreased as precipitation increased; there was lessactivity in rain than in snow and less activity in wet snow than in drysnow. Activity did not vary significantly with depth of snow until snowwas more than 8 inches deep, when activity decreased abruptly. The average of the longest distance traveled between captures forcottontails whose entire home ranges were thought to have been sampledwas 900 feet for males and 684 feet for females. The average of themaximum distance across the home range for cottontails whose home rangehad been thoroughly sampled was 1019 feet for males, and 936 feet forfemales. The home range is used by the cottontail in different ways, dependingon the needs of the individual and the condition of the habitat. Inuniform habitat the home range is roughly circular and is used mostnear its center and least toward its periphery. The entire home rangeis traversed every four or five days. The center of the home range hasbeen called the "center of activity" (Connell, 1954). In habitat of alternating woodland and grassland, such as that on theUniversity of Kansas Natural History Reservation, two centers ofactivity often developed in the home range of a cottontail, at oppositeedges of a tract of woodland. The individual concentrated its movementsnear one center for three to five days then moved to the other center. Pursuit by a predator, random movement, or other cause may beresponsible for shift from one edge to another. PLATE 45 [Illustration: FIG. 1. "House Field" viewed from the northeast corner, looking southwest, March 3, 1956, showing the condition of vegetationin winter. Traps were operated on a 50-foot grid throughout this area. ] [Illustration: FIG. 2. Same area as above, on July 10, 1956, showingthe condition of vegetation in summer. ] PLATE 46 [Illustration: FIG. 1. View southeast from the north edge of "PicnicField" showing condition of the vegetation on December 3, 1954. Traplines were placed along woodland edge from which this picture wastaken, along road where vehicle is parked, along creek beyond road, along edge of field beyond creek, and along edge of woods inbackground. ] [Illustration: FIG. 2. Summer aspect of the vegetation, on July 14, 1955; same view as shown in Fig. 1. ] PLATE 47 [Illustration: FIG. 1. Condition of vegetation along woodland bordernortheast of Reservation headquarters on December 3, 1954. Camera wasfacing southwest. Traps were operated along this edge and in woods toright and in background. ] [Illustration: FIG. 2. Condition of vegetation at edge of "House Field"on July 14, 1955. Scale is shown by 4-1/2 foot tripod. Brome grass wasapproximately two feet high. Traps were operated in a grid in thisarea. ] PLATE 48 [Illustration: FIG. 1. Cottontail in bag with ear protruding, ready formarking with nylon ribbon and metal ear-tag shown in upper right handcorner. × 1/4. ] [Illustration: FIG. 2. Cottontail bearing ear-tags and ribbon. × 1/4. ] When moving undisturbed through the woods cottontails usually do notpause to forage or associate with other cottontails, but keep to astraight route except in severe weather, when, as noted above, theyfind resting places in the woods. Ninety-two per cent of thecottontails captured in live-traps were captured within 100 feet of awoodland edge; six per cent were captured in the woods, more than 100feet from an edge, and two per cent were captured in grassland morethan 100 feet from the edge. In winter, when the air temperature wasless than 20° F. , 22 per cent of the cottontails were capturedin the woods more than 100 feet from the edge. The maximum distance between two centers of activity of an individualwas 700 feet, average 550 feet. If two centers of activity weremaintained, the cottontail usually traversed the entire home rangeevery seven to 11 days. In no case was a cottontail known to have lived in two woodland edgeswhich were separated by open grassland. Cottontails usually did notmove more than 75 feet from suitable cover. In winter when herbaceousvegetation was dormant cottontails did not cross open fields. Forms in grass clumps were the usual resting place for cottontails, butothers in brush piles, rock outcrops, and tree stumps were also used. On the average a cottontail maintained 3. 5 forms. If disturbedrepeatedly at a form, a cottontail would permanently desert it. Onseven occasions a cottontail used a form that had been used by anotherwithin 24 hours. Three cottontails used the same shelter under a rockledge in five days; one was under the ledge on December 17, 1955, andanother was there on December 18. The first was there again on December20 and a third was there on December 21. The original cottontail hadreturned by January 2, 1956. There may be 20 to 30 resting places usedby cottontails within a single home range area since five to sevencottontails may live there as co-occupants at one time. Twocottontails, both males, lived together in a _Smilax_ thicket for threeweeks, resting within 15 inches of each other. Occasionally a femalewas present in the same thicket, and rested about three feet from themales. A male trapped on land adjoining the Reservation and confined overnightat the Reservation headquarters escaped the next day and was seen 32days later, 1800 feet from the point of escape, back in the area whereit was originally captured. A female confined for observation, escaped and ran in the directionopposite from her home. Subsequently she was seen on four differentoccasions, over a period of one month, in her original home range, 1, 100 feet from the point where she escaped. Both these animals whichmade homing movements had been removed in cloth bags from their homes. Another cottontail removed from its home range and taken to thelaboratory building to be marked, escaped and ran to a nearby woodedhillside without pursuit where it could be observed because of snow onthe ground and lack of leaves on the trees. The animal ran and hoppedabout over a one-half acre area. Its movements seemed to be unorientedand it frequently stopped and stood on its hind legs in order to lookabout. After 10 minutes of this behavior, a red-tailed hawk (_Buteojamaicensis_) screamed as it flew overhead. The cottontail, stimulatedby seeing and/or hearing the hawk, ran faster, moving in circles untilit disappeared from view five minutes later. When last observed thecottontail was 1, 700 feet from its home range and was headed in theopposite direction. It had passed several potential shelters but hadnot attempted to use them, presumably because it was not familiar withthe area. Although for several months afterward traps were operated inthe cottontail's home range area and in the area where it escaped, theanimal was never recaptured. SIZE AND SHAPE OF HOME RANGE Of the 89 cottontails observed in the study, 35 were captured inlive-traps only once and were never seen in the field or trailed. Theremaining 54 served for calculation of home range by one or moremethods. The minimum, maximum and average home ranges for these 54individuals were calculated by each of five methods. All individualsfor which any area was recorded were included in the average. Incomplete home ranges lower the averages. According to the mostreliable method (Composite Method) 30 male cottontails had home rangesof between 0. 46 acre and 12. 19 acres and 24 female cottontails had homeranges of between 0. 46 acre and 12. 62 acres. The average for males was5. 05 acres and the average for females was 4. 81 acres. The average forall 54 cottontails was 4. 86 acres. Because of irregularities in live-trapping and field observation somecottontails were more intensively studied than were others; onecottontail was followed one time only, while another was trapped 26times, followed three times, and seen in the field six times. It wasnecessary to determine which cottontails had been studied sufficientlyto determine the approximate extent of their home ranges. [Illustration: FIG. 1. Correlation between average size of home rangeand number of "peripheral points" (marginal records, which form angleswhen the range is outlined). On the average, a sufficient number ofrecords to yield approximately nine peripheral points must be obtainedbefore the full extent of the home range is revealed. ] The average area, in acres, of home range was plotted, on a graph, against the number of peripheral points (Figure 1). When a home rangehad nine or more peripheral points, on an average, the size of homerange did not increase significantly with additional captures, observations in the field, or records of trails. Home ranges with lessthan nine peripheral points were likely to be increased in size witheach new observation. A similar situation has been shown by previousauthors who have plotted the size of home range against number ofcaptures in live-traps, where only live-trapping was used to gatherdata. Therefore, in my study, home ranges with nine or more peripheralpoints were considered to be adequately studied. Data for eighteen cottontails that had been studied sufficiently todetermine the full extent of their home ranges were used to calculateminimum, maximum, and average home range by each of five methods (Table1). The methods used by Schwartz (1941), Dalke and Sime (1938) andAllen (1939) yielded results which were lower than any others, presumably because only live-trap data were used and because straightlines were used to connect traps in which cottontails were captured. The "composite method" was considered the most reliable because itutilized all data gathered for each individual and because with thismethod the home range boundaries were drawn to enclose all areas inwhich the cottontail lived and excluded all areas in which thecottontail was not known to have been. The method used by Fitch (1949)agreed most closely with the "composite method" and suggests to me thatthe home range of animals can be estimated with reasonable accuracy bythis method when field observation or trailing are not feasible. Thecomposite method is superior to others for studying the home range andmovements of cottontails. Of the individuals whose entire home ranges had been thoroughlystudied, nine males had home ranges of between 4. 72 acres and 12. 19acres with an average of 8. 92 acres; nine females had home ranges ofbetween 2. 42 acres and 12. 62 acres with an average of 7. 76 acres. Theaverage size of home range for both sexes was 8. 34 acres (Table 1). TABLE 1. --HOME RANGES, IN ACRES, OF 18 COTTONTAILS ON THERESERVATION IN 1956, COMPUTED BY FIVE DIFFERENT METHODS. ======================================================================= | | Number of | Average | Maximum | Minimum Method | Sex | individuals| area | area | area----------------------+-----+------------+---------+---------+---------Allen (1939), | (M) | 9 | 2. 00 | 6. 78 | . 30Dalke and Sime (1938) | (F) | 9 | 2. 54 | 7. 20 | . 35and Schwartz (1941) | all | 18 | 2. 27 | 7. 20 | . 30 +-----+------------+---------+---------+--------- | (M) | 9 | 4. 01 | 12. 89 | 1. 05Fitch (1947) | (F) | 9 | 5. 68 | 11. 50 | 1. 84 | all | 18 | 4. 85 | 12. 89 | 1. 05 +-----+------------+---------+---------+--------- | (M) | 9 | 7. 20 | -- | --Fitch (1949) | (F) | 9 | 9. 00 | -- | -- | all | 18 | 8. 40 | -- | -- +-----+------------+---------+---------+---------Tracking and | (M) | 9 | 8. 74 | 11. 15 | 3. 54field observations | (F) | 9 | 8. 62 | 12. 18 | 5. 51 | all | 18 | 8. 69 | 12. 18 | 3. 54 +-----+------------+---------+---------+---------Tracking and field | (M) | 9 | 8. 92 | 12. 19 | 4. 72observations plus | (F) | 9 | 7. 76 | 12. 62 | 2. 42live-trapping | all | 18 | 8. 34 | 12. 62 | 2. 42----------------------+-----+------------+---------+---------+--------- [Illustration: FIG. 2. Maps showing home ranges of cottontails inrelation to woodland and open fields on the study area. One inch equalsapproximately 470 feet. Each home range is shown slightly rounded fromthe polygonal figures obtained by connecting actual points where theanimal was recorded. _Upper Left. _ An area of 4. 6 acres occupied by acottontail in winter, increased to 6. 5 acres in summer by the animalcrossing a narrow grassland strip to another woodland edge. _LowerLeft. _ Showing increasing size of home range of a female cottontail; inJuly, 1954 (at age of three weeks), she had a range of . 25 acre;September, 1954, 1. 5 acres; December, 1954, 8 acres; and December, 1955, 11 acres. _Right Half. _ Two home ranges of a cottontail whichmoved from its original area to occupy a new one 410 feet farther northacross a field in September and October, 1955. ] Cottontails range over a larger area in summer than they do in winterbecause suitable cover and food is more abundant in summer. Onecottontail (Figure 2, upper left) lived in a woodland home range of 4. 6acres in the winter but increased the range to 6. 5 acres in summer bycrossing the narrow overgrown end of a field to another woodland area. Another cottontail (Figure 3, top part) lived in a woodland home rangeof 7. 9 acres in winter but in summer increased the home range to 9. 5acres by including also a part of an adjacent field. Other cottontailsincreased their home ranges in summer by five to 15 per cent. On the average, male cottontails had a larger (by 13 per cent) homerange than females probably because of the increased activity of malesin the breeding season and the decreased activity of females whenpregnant and caring for young. Nevertheless, some of the largest homeranges measured were those of females. [Illustration: FIG 3. Diagrams showing home ranges of cottontails inrelation to woodland and open fields on the study area. One inch equalsapproximately 545 feet. Each home range is shown slightly rounded fromthe polygonal figures obtained by connecting actual points where theanimal was recorded. _Upper. _ Winter range of 7. 9 acres (solid line)increased to 9. 5 acres in summer by area in dashed line. _Lower. _Overlapping home ranges of four of the many cottontails living on thestudy area. Each of the four cottontails occupied approximately thesame home range throughout the year. ] The size of the home range in immature cottontails varies between 0. 1acre and 4. 0 acres, depending on the age and size of the individual. Fourteen young cottontails between three and six weeks of age did notleave areas of approximately one acre in each instance. Ninecottontails between six weeks and 18 weeks of age lived in areas ofabout two acres. By the time cottontails are four to five months oldthey inhabit a home range of four to eight acres. One cottontail (Figure 2, lower left) born in July, 1954, was estimatedto have wandered over approximately 0. 25 acre at an age of three weeks. In September this cottontail occupied a home range of one and one-halfacres. By December it was five months old and occupied an area of abouteight acres. In the next year it enlarged its home range to 11. 5 acres. The cottontail usually settles down in one area and stays there untilit dies. Changes from one home range to another are unusual, but minorshifts, in response to changes in vegetation and weather, are common. In one exceptional instance (Figure 2, right) a male cottontail, occupying a home range of 11. 2 acres in a woodland, suddenly shifted toa new area that barely overlapped its former home range at one edge. Two months after the change was first noticed the cottontail was livingin a new home range of 6. 6 acres 300 feet from its original home range. In changing from one home range to the other the cottontail traveledalong a dry stream bed and was captured there three times. Maps of the home ranges of four of those 18 cottontails for whichsufficient data were collected to determine the size of home range areshown in the lower part of Figure 3. SUMMARY AND CONCLUSIONS The home range and movements of the cottontail were studied on a90-acre area of the University of Kansas Natural History Reservationfrom February, 1954, to March, 1956. Eighty-nine cottontails wereidentified in the field 59 times, trailed 70 times and captured inlive-traps 326 times in 7, 850 trap nights. Home range of the cottontailwas calculated by five methods, using the same set of data, and theresults were compared. A composite method was used, which permitted theuse of more data than any other one method. The maintenance of a home range is of survival value to the cottontail. Knowledge of the home range is of value to man when control orpropagation of cottontail populations is desired. Cottontails establisha home range where they are born and enlarge it to nearly full size thefirst winter. Home ranges of cottontails are overlapped by those ofothers regardless of sex or age. No territory is maintained. The cottontail makes movements to forage, to seek cover from predatorsand the weather, to reproduce, build nests, care for young, keep pacewith changes in vegetation through the year, and escape unusuallysevere climatic conditions. Movements may be caused by desire foracquaintance with surroundings and other animals, escape fromundesirable surroundings or animals, or merely release of nervousenergy. When foraging, cottontails moved 175 to 325 feet per day, mostly nearwoodland edges, and used from 10 to 20 per cent of the home range. Whenescaping from predators cottontails moved 30 to 1200 feet and used 5 to70 per cent of their home ranges, depending on the type of pursuit. Some cottontails that were followed, ran in almost circular courses foras far as 3000 feet and covered as much as 90 per cent of their homeranges. Paths or runways were not used except in deep snow or verydense vegetation. Movements were limited by deep snow. Whentemperatures were unfavorably high or low, cottontails sought coverdeep in the woods or under rock outcrops, and in dry stream beds. Inmoderate weather resting places in grass forms, brush piles andthickets were used. Both males and females moved farther in the breeding season than in therest of the year, but females that were caring for young in summer andlate spring moved shorter distances than they did when not so engagedin autumn and winter. Cottontails were most active at dawn and especially, dusk, and weremore active on dark nights than on moonlight nights. Cottontails weremost active when the air temperature was between 0° F. And 33° F. Andwhen rain was not falling. Activity increased as the percentage ofground covered by snow increased and as the abundance of fooddecreased. Activity did not vary with physiological condition exceptthat as body weight decreased activity increased--probably because oflack of food. The home range is used most intensively near centers of activity thatare near woodland edges or in other areas of good cover. Cottontailsoften ranged through the woods and along edges but did not cross openareas more than 75 feet wide. Cottontails use their home range mostintensively in winter when they are forced to move long distances inpoor cover, searching for food. More than one cottontail may use sitesof good cover at the same time and two or three used the same restingplace at different times. Two instances of homing were observed; cottontails moved 1, 100 and1, 800 feet to return to their home ranges, but one cottontail thatescaped 1700 feet from home failed to return. The average home range of 18 cottontails for whom adequate data weregathered was 8. 34 acres. The home ranges of males averaged 1. 16 acrelarger than those of females. In summer, cottontails increased theirhome ranges 5 to 15 per cent by taking advantage of cover provided bythe more abundant vegetation. Cottontails three weeks to five months ofage lived in home ranges of between 0. 1 and 4. 0 acres and enlargedtheir home ranges almost to their ultimate full size in the firstwinter. LITERATURE CITED ALLEN, D. L. 1939. Michigan cottontails in winter. Jour. Wildl. Mgt. , 3(4):307-322, 6 half-tone pls. , 7 tables. CONNELL, J. H. 1954. Home range and mobility of brush rabbits in California Chaparral. Jour. Mamm. , 35(3):392-405, 6 figs. , 2 tables. DALKE, P. D. 1937. A preliminary report of the New England Cottontail studies. Trans. Second North Amer. Wildl. Conf. , 542-548. 1942. The cottontail rabbits in Connecticut. State of Connecticut Public Document No. 47, State Geological and Natural History Survey Bull. No. 65. 1-97 pp. , 22 figs. , 43 tables. DALKE, P. D. , and SIME, P. R. 1938. Home and seasonal ranges of the eastern cottontail in Connecticut. Trans. Third North Amer. Wildl. Conf. , 659-669 pp. , 4 figs. , 9 tables. FITCH, H. S. 1947. Ecology of a cottontail rabbit (_Sylvilagus auduboni_) population in Central California. California Fish and Game, 33(3):159-184, 48-53 figs. , 8 tables. 1949. Study of snake populations in Central California. Amer. Midl. Nat. , 41(3):513-579, 11 figs. , 28 tables. 1950. A new style live-trap for small mammals. Jour. Mamm. , 31(3):364-365, 1 fig. 1952. The University of Kansas Natural History Reservation. Univ. Kansas Mus. Nat. Hist, Misc. Publ. No. 4:1-38, 4 pls. , 3 figs, in text. HALL, E. R. 1951. A synopsis of the North American Lagomorpha. Univ. Kansas Publs. , Mus. Nat. Hist. , 5(10):119-202, 68 figs. In text. HAUGEN, A. O. 1942. Home range of the cottontail rabbit. Ecology, 23(3):354-367, 6 figs. , 9 tables, 1 graph. HAYNE, D. W. 1949. Calculation of size of home range. Jour. Mamm. , 30(1):1-18, 2 figs. , 2 tables. HENDRICKSON, G. O. 1936. Summer studies on the cottontail rabbit; _Sylvilagus floridanus_. Iowa State Coll. Jour. Sci. , 10:367-372. JANES, D. W. 1957. Body temperature in the eastern cottontail. Jour. Mamm. , 38 (1):137. LEONARD, A. B. , and GOBLE, C. R. 1952. Mollusca of the University of Kansas Natural History Reservation. Univ. Kansas Sci. Bull. , 34:1013-1055. MARTIN, E. P. 1956. A population study of the prairie vole (_Microtus ochrogaster_) in northeastern Kansas. Univ. Kansas Publs. , Mus. Nat. Hist. , 8(6):361-416, 19 figs. In text. PACKARD, R. L. 1956. The tree squirrels of Kansas: Ecology and economic importance. Univ. Kansas Mus. Nat. Hist. , Misc. Publ. No. 11:1-67, 10 figs, in text, 2 pls. SALMAN, D. H. 1948. On the home range of cottontails. Physiologia Comparata et Oecologia, 1(2):95-109. SCHWARTZ, C. W. 1941. Home range of the cottontail in central Missouri. Jour. Mamm. , 22(4):386-392, 1 fig. , 2 tables. STEBLER, A. M. 1939. The tracking technique in the study of the larger predatory mammals. Trans. Fourth North Amer. Wildl. Conf. , 203-208.