46 



John B. Calhoun 



(see Fig. 20) . As might be expected, as home range centers get closer to- 

 gether the probability of any individual contacting neighbors at every 

 distance from its home range center increases. There may be some fre- 

 quency of contacting neighbors which becomes so unbearable to the in- 

 dividual that his resultant aggressive actions prevent further contraction 

 of the interval between home range centers. However, we have no basis 

 for gaining insight as to what this frequency might be. 



0.1 r- 



•- -^ .01 



L. < 



O t- 



-I q: 



m "^ 



o 



tc 



a. 



.001 



.0002 ■- 



0.6 1.2 1.8 2.4 3.0 



<r DISTANCE FROM ANY H.R.C. 



Fig. 20. Contacting neighbors. The relative probability of any one individual meet- 

 ing others with reference to its distance from its own home range center, and to the 

 distance between home range centers of all individuals. 



One characteristic of these curves of relative probability of contacting 

 neighbors does lend itself to suggesting a condition leading to an optimum 

 interval between home range centers. When HRC's are 2.1 sigma apart 

 the probability of contacting neighbors up to half the distance between 

 home range centers is for all practical purposes constant. Applying this 

 insight to all members of the population, it is apparent that with HRC's 

 this distance apart, the probability of contact between neighbors becomes 

 relatively constant everywhere. If we accept the principle elaborated by 



