cottontail (Figure 2, upper left) lived in a woodland home range of 4.6 acres in the winter but increased the range to 6.5 acres in summer by crossing the narrow overgrown end of a field to another woodland area. Another cottontail (Figure 3, top part) lived in a woodland home range of 7.9 acres in winter but in summer increased the home range to 9.5 acres by including also a part of an adjacent field. Other cottontails increased their home ranges in summer by five to 15 per cent.

On the average, male cottontails had a larger (by 13 per cent) home range than females probably because of the increased activity of males in the breeding season and the decreased activity of females when pregnant and caring for young. Nevertheless, some of the largest home ranges measured were those of females.

Fig 3. Diagrams showing home ranges of cottontails in relation to woodland and open fields on the study area. One inch equals approximately 545 feet. Each home range is shown slightly rounded from the polygonal figures obtained by connecting actual points where the animal 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 the study area. Each of the four cottontails occupied approximately the same home range throughout the year.

The size of the home range in immature cottontails varies between 0.1 acre and 4.0 acres, depending on the age and size of the individual. Fourteen young cottontails between three and six weeks of age did not leave areas of approximately one acre in each instance. Nine cottontails between six weeks and 18 weeks of age lived in areas of about two acres. By the time cottontails are four to five months old they inhabit a home range of four to eight acres.

One cottontail (Figure 2, lower left) born in July, 1954, was estimated to 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-half acres. By December it was five months old and occupied an area of about eight 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 until it dies. Changes from one home range to another are unusual, but minor shifts, 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 to a new area that barely overlapped its former home range at one edge. Two months after the change was first noticed the cottontail was living in 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 traveled along a dry stream bed and was captured there three times.

Maps of the home ranges of four of those 18 cottontails for which sufficient data were collected to determine the size of home range are shown in the lower part of Figure 3.

SUMMARY AND CONCLUSIONS

The home range and movements of the cottontail were studied on a 90-acre area of the University of Kansas Natural History Reservation from February, 1954, to March, 1956. Eighty-nine cottontails were identified in the field 59 times, trailed 70 times and captured in live-traps 326 times in 7,850 trap nights. Home range of the cottontail was calculated by five methods, using the same set of data, and the results were compared. A composite method was used, which permitted the use 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 or propagation of cottontail populations is desired. Cottontails establish a home range where they are born and enlarge it to nearly full size the first winter. Home ranges of cottontails are overlapped by those of others regardless of sex or age. No territory is maintained.

The cottontail makes movements to forage, to seek cover from predators and the weather, to reproduce, build nests, care for young, keep pace with changes in vegetation through the year, and escape unusually severe climatic conditions. Movements may be caused by desire for acquaintance with surroundings and other animals, escape from undesirable surroundings or animals, or merely release of nervous energy.

When foraging, cottontails moved 175 to 325 feet per day, mostly near woodland edges, and used from 10 to 20 per cent of the home range. When escaping from predators cottontails moved 30 to 1200 feet and used 5 to 70 per cent of their home ranges, depending on the type of pursuit. Some cottontails that were followed, ran in almost circular courses for as far as 3000 feet and covered as much as 90 per cent of their home ranges. Paths or runways were not used except in deep snow or very dense vegetation. Movements were limited by deep snow. When temperatures were unfavorably high or low, cottontails sought cover deep in the woods or under rock outcrops, and in dry stream beds. In moderate weather resting places in grass forms, brush piles and thickets were used.

Both males and females moved farther in the breeding season than in the rest of the year, but females that were caring for young in summer and late spring moved shorter distances than they did when not so engaged in autumn and winter.

Cottontails were most active at dawn and especially, dusk, and were more active on dark nights than on moonlight nights. Cottontails were most active when the air temperature was between 0° F. and 33° F. and when rain was not falling. Activity increased as the percentage of ground covered by snow increased and as the abundance of food decreased. Activity did not vary with physiological condition except that as body weight decreased activity increased—probably because of lack of food.

The home range is used most intensively near centers of activity that are near woodland edges or in other areas of good cover. Cottontails often ranged through the woods and along edges but did not cross open areas more than 75 feet wide. Cottontails use their home range most intensively in winter when they are forced to move long distances in poor cover, searching for food. More than one cottontail may use sites of good cover at the same time and two or three used the same resting place at different times.

Two instances of homing were observed; cottontails moved 1,100 and 1,800 feet to return to their home ranges, but one cottontail that escaped 1700 feet from home failed to return.

The average home range of 18 cottontails for whom adequate data were gathered was 8.34 acres. The home ranges of males averaged 1.16 acre larger than those of females. In summer, cottontails increased their home ranges 5 to 15 per cent by taking advantage of cover provided by the more abundant vegetation. Cottontails three weeks to five months of age lived in home ranges of between 0.1 and 4.0 acres and enlarged their home ranges almost to their ultimate full size in the first winter.

LITERATURE CITED

Allen, D. L.

Connell, J. H.