GROUP BEHAVIOR 1 35 



floor and make their presence known by a series of 

 snaps, whirrs and calls which may be heard as far as 

 three hundred yards. The females, who are more 

 quiet and retiring, apparently are attracted by the 

 line of males; they come individually from the sur- 

 rounding thickets and each mates with one of the 

 males. The evidence suggests that they are attracted 

 from a greater distance by the spaced aggregation of 

 males than they would be by isolated courting places. 

 The more or less organized line of males in breeding 

 condition apparently facilitates the mating of these 

 jungle birds. 



This is a highly specialized example of the wide- 

 spread phenomenon of territoriality which can be 

 recognized even among breeding fishes, (103) and 

 which has been much studied of recent years in birds. 

 (65) Typically the male birds arrive first in the 

 spring and take up fairly well-defined territories in 

 the same general area, which they defend from in- 

 truding males. Then the females come in and flit 

 from territory to territory before settling down to 

 raise a brood with one particular male. There is 

 always the strong suggestion that the presence of a 

 number of singing males, even if spaced about in 

 different territories, attracts and hastens the accept- 

 ance of some one of them by an unmated female. 



Group stimulation of the amount of food taken 



