48 



John B. Calhoun 



dividual with sufficient intensity to produce a response by the latter in so 

 long as the indiA'iduals are separated by a distance no greater than 3 home 

 range sigma. In all probability, signals in the sense of vocalizations are 

 emitted by each individual periodically as they wander through their 

 home range. In order to simplify calculation of the signal field of neighbors, 

 the particular condition was taken where all signals are emitted only from 

 the home range centers. Thus, along a typical route of travel, as shown by 

 the heavy dashed line in Fig. 1(), the sum of the intensity of signals from 

 all neighbors was calculated. 



0.6 1.2 1.8 2.4 



a DISTANCE FROM ANY H.R.C. 



Fig. 21. Sign field of neighbors. Signs are considered as any persisting indication of 

 an animal having made a response, i.e., defection, gnawings, or removal of food items. 

 Thus Fig. 21 essentially represents the subtraction of the density function of one indi- 

 vidual from the sum of the density functions of all individuals as shown in Fig. 19. 



Again, we might wonder what standard the individual might utilize in 

 judging the total intensity of signals received. Since the learning of the 

 signal presupposes emission by one individual and detection by the other 

 when they are in contact, this level of intensity with an assigned value of 

 1.0 may be taken as the standard. Since the intensity of signals probably 

 drops off inversely proportional to distance, the sum of signals at any 

 point in place and time may be less than 1.0. A further complication to the 

 problem is that all neighbors may not emit signals simultaneously. Simul- 

 taneity other than by chance will arise regularly only if the detection of the 



