1. The Social Use of Space 79 



time A emerges and starts on an outward excursion ho experiences a bom- 

 bardment by so many a signals that his trip is shortly terminated and he 

 returns home. In a similar fashion, 5's home range will become contracted 

 but not so much as A's because A does not emit h signals, whose sum at 

 any one time is contributed to only by species B, C, and D. C will have 

 only a slightly inhibited home range since it is responsive only to signals 

 contributed by itself and D. At the apex of the system members of species 

 D are influenced only by d. 



At the psychological apex of the community, further differentiation 

 occurs among the members of the dominant, D species. According to the 

 formulation developed in Section VIII, C, members of this species have the 

 capacity to differentiate into alpha, beta, and gamma members. Their 

 basic c?-type signal becomes differentiated into (/„, dis, and dy components. 

 Alpha individuals possess all three; beta members only d^ and dy] while 

 gamma members emit only dy. 



This purely theoretical formulation predicts that home range size and 

 complexity of signals emitted are positively correlated. The observed 

 data on removal captures lead to inferences of home range expansion 

 following removal of associates. Intra- and interspecific inhibitions are so 

 apparent as to demand the minimum assumptions made above for main- 

 taining such a complex spatial organization of the small-mammal com- 

 munity. Compare these formulations with those of "velocity" developed 

 in Sections XIII, A; XIV, A; and XIV, E and F. Such comparison leads 

 to the conclusion that the greater an individual's velocity, the more com- 

 plex will be the pattern of signals he emits. 



Psychological dominance is then the ability to inhibit the home range of 

 others resulting from the fact that the dominant shares certain signal 

 characteristics with the subordinate, but in addition possesses signals 

 which the subordinate lacks. The sharing of a signal by a species with 

 another species which it usually dominates may lead to mutual inhibition 

 of home range or actual reversal of roles. 



Consider the Clethrionomijs and Peromyscus relationship. The greater 

 frequency with which Clethrionomijs appears to be dominant to Peromyscus 

 suggests that it has the c-rZ-type signal while Peromyscus has only c. We 

 may ignore other shared characteristics of their signals. In fact, we may 

 focus only on the shared c component. Chance vagaries of the system may 

 from time to time, after a crash in the populations of both species, result in 

 a marked preponderance of Peromyscus over Clethrionomys. Similarly, at 

 the southern periphery of its range, we can expect Peromyscus frequently 

 to be more dense than Clethrionomys. Clethrionomys will then meet too 

 infrequently to make any associations with their own species' specific 

 signal. However, encounters will occur more frequently between Clethri- 



