62 John B. Calhoun 



stellatioii formation presupposes passing through a stage of uniform dis- 

 tribution of home ranges. In the interstices between the home ranges of 

 alpha species there is the opportunity for very subordinate species with 

 highly contracted home ranges to establish themselves. As the constellation 

 forms, certain members of the subordinate species will be retained within 

 the interstices of the constellation while others will lie at its periphery. 

 However, as constellations form, there develops an interconstellation 

 matrix rarely frequented by members of the alpha species. We may then 

 wonder what members of the community will live here. 



At this point, the Huntington Forest censuses of 1952 and 1953 (Fig. 11) 

 are particularly instructive. The red-backed mouse, Clethrionomys, is ob- 

 viously the alpha species. Just as obviously, the shrew Sorex is the most 

 subordinate species, which has highly contracted home ranges lying in the 

 interstices between those of Clethrionomys. Had all these census been run 

 for longer than 30 days, it looks as though the 2 : 1 ratio of the alpha species 

 to one of its most subordinate associates would have been realized. Censuses 

 shown from other areas indicate that both Peromyscus and Blarina are 

 dominant to Sorex in the community. And yet, in these Huntington 

 Forest censuses, relatively few of either were caught. What I suspect has 

 happened is that as the constellations developed, both species were relegated 

 to the interconstellation matrix, where they existed in somewhat contracted 

 home ranges, as indicated by the catch per day increasing from day 1 to 

 days 4-6. In fact, for both these species it looks as though a certain portion 

 of their members had even more markedly contracted home ranges. This 

 is indicated by the secondary increase in catch per day starting betw^een 

 days 8 and 10. 



D. Expected Variability in the Number of Individuals Forming 

 Constellations 



In terms of the formulation of Section VIII, C the six nearest neighbors 

 to any alpha individual will always be attracted toward it as the members 

 of a population wuth a uniform distribution of home range centers begin 

 to form diffuse clumps, termed constellations. The twelve next-nearest 

 neighbors to any alpha individuals may be divided into two types, a and h, 

 according to their probability of being attracted toward any given alpha 

 neighbor. 



Let: a represent the six individuals who have a probability, pa = 2, of 

 being attracted to any given alpha. 

 h represent the six individuals who have a probability, 'Pb = k, of 

 being attracted to any given alpha. 



