64 John B. Calhoun 



• • • p (7 + 12) since the constellation becomes composed of the addition 

 of these next-nearest neighbors, or gamma individuals to the basic core of 

 the one alpha and its six beta nearest neighbors. 



E. Social Rank and Intraspecific Associations 



In the 14-day removal study shown in Fig. 13B, trapping results indi- 

 cated large home ranges for Peromyscus, moderate-sized ones for Blarina, 

 and highly contracted home ranges for Pitymys. Estimated home range 

 sigmas, o-, of 50, 25, and 12.5 feet, respectively, probably closely enough 

 approximate the real values to permit their use in a study of these data. 

 If we knew the actual home range centers of all animals trapped, a 1-sigma 

 radius circle plotted about each on a map of the study area should pro\'ide 

 more insight into spatial relationships. 



Since such centers were not known, they were approximated by making 

 the following assumptions: 



1. Peromyscus maximize inter-home-range-center distance from other 

 Peromyscus. 



2. Blarina similarly maximize distance, not only from others of theu' 

 own kind, but also from Peromyscus. 



3. Pitymys maximize distance from both Peromyscus and Blarina, as 

 well as from others of their own kind. 



4. The later an animal was trapped the farther its home range centers 

 were located from the trapline. 



For Peromyscus some of the HRC's were shifted to one side of the line 

 of capture, and the remaining to the other side, until ever}'' adjacent 3 

 HRC's approximated equilateral triangles. A similar procedure was ap- 

 plied to Blarina captures except that where possible their HRC's also 

 were placed in the center of triangles formed by the HRC's for Peromyscus. 

 Then the HRC's for Pitymys w^ere, insofar as possible, placed in the centers 

 of triangles connecting the HRC's of the other two species. 



Utilizing these assumptions, centers of home ranges for Peromyscus 

 were plotted first, Blarina second, and Pitymys last. Originally these were 

 all plotted on a single figure, but for the sake of greater clarity in examining 

 intraspecific relations the home ranges, in terms of 1-sigma circles, are 

 shown separately in Figs. 28-30. 



Moisture conditions in the habitat varied markedly. Steep xerophytic 

 slopes of oak and pine covered the three sectors encompassed between the 

 E and SW radii. The sector between the N and NW radii was quite steep 

 and dry. A damp drainage area lay roughly along the W and NE radii. 



