in the average. Incomplete home ranges lower the averages. According to the most reliable method (Composite Method) 30 male cottontails had home ranges of between 0.46 acre and 12.19 acres and 24 female cottontails had home ranges of between 0.46 acre and 12.62 acres. The average for males was 5.05 acres and the average for females was 4.81 acres. The average for all 54 cottontails was 4.86 acres.

Because of irregularities in live-trapping and field observation some cottontails were more intensively studied than were others; one cottontail was followed one time only, while another was trapped 26 times, followed three times, and seen in the field six times. It was necessary to determine which cottontails had been studied sufficiently to determine the approximate extent of their home ranges.

Fig. 1. Correlation between average size of home range and number of "peripheral points" (marginal records, which form angles when the range is outlined). On the average, a sufficient number of records to yield approximately nine peripheral points must be obtained before 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 range had nine or more peripheral points, on an average, the size of home range did not increase significantly with additional captures, observations in the field, or records of trails. Home ranges with less than nine peripheral points were likely to be increased in size with each new observation. A similar situation has been shown by previous authors who have plotted the size of home range against number of captures in live-traps, where only live-trapping was used to gather data. Therefore, in my study, home ranges with nine or more peripheral points were considered to be adequately studied.

Data for eighteen cottontails that had been studied sufficiently to determine the full extent of their home ranges were used to calculate minimum, maximum, and average home range by each of five methods (Table 1). The methods used by Schwartz (1941), Dalke and Sime (1938) and Allen (1939) yielded results which were lower than any others, presumably because only live-trap data were used and because straight lines were used to connect traps in which cottontails were captured. The "composite method" was considered the most reliable because it utilized all data gathered for each individual and because with this method the home range boundaries were drawn to enclose all areas in which the cottontail lived and excluded all areas in which the cottontail was not known to have been. The method used by Fitch (1949) agreed most closely with the "composite method" and suggests to me that the home range of animals can be estimated with reasonable accuracy by this method when field observation or trailing are not feasible. The composite method is superior to others for studying the home range and movements of cottontails.

Of the individuals whose entire home ranges had been thoroughly studied, nine males had home ranges of between 4.72 acres and 12.19 acres with an average of 8.92 acres; nine females had home ranges of between 2.42 acres and 12.62 acres with an average of 7.76 acres. The average size of home range for both sexes was 8.34 acres (Table 1).

Table 1.—Home Ranges, in Acres, of 18 Cottontails on the Reservation in 1956, Computed by Five Different Methods.

Fig. 2. Maps showing home ranges of cottontails in relation to woodland and open fields on the study area. One inch equals approximately 470 feet. Each home range is shown slightly rounded from the polygonal figures obtained by connecting actual points where the animal was recorded. Upper Left. An area of 4.6 acres occupied by a cottontail in winter, increased to 6.5 acres in summer by the animal crossing a narrow grassland strip to another woodland edge. Lower Left. Showing increasing size of home range of a female cottontail; in July, 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 which moved from its original area to occupy a new one 410 feet farther north across a field in September and October, 1955.

Cottontails range over a larger area in summer than they do in winter because suitable cover and food is more abundant in summer. One