PSYCHOLOGY AND BEHAVIOR 



69 



course of experiments, have many times observed the reactions on which Allen's conclusions 

 were based. Complete records taken twice a day of the occurrence of each phase in all the 

 breeding grouse at the Research Center over a period of two spring seasons have also been 

 kept (table 7). Analyzing these, a different interpretation is here suggested. 



Let us consider for a moment the matter of sex recognition. Unquestionably male grouse 

 may display to a bird of either sex or even to unfamiliar objects, as previously mentioned, 

 during the height of their display phase. At other times the presence of a female seems more 

 likely to stimulate this response by the male. Likewise, place both a female and a male with a 

 displaying cock for a few minutes and, providing one bird is not too over-dominant, the 

 latter will often intensify its strutting in the direction of the female and exhibit a desire to 

 fight the male. Two cocks do not commonly display to each other. Nevertheless, as suggested, 

 one function of strutting may be intimidation. 



No evidence has been noted of a recurrent sex rhythm in the male. True, as described by 

 Allen, there are times during all of the three phases when most male grouse will mate with 

 another bird if it be posturing and other days when such birds will not mate at all. In the 

 first place, strutting, to which, at the height of excitation, the hissing and headshaking reactions 

 are added, is ])redominant. The second phase, characterized by gentleness and head-twitching, 

 follows in turn, to be superseded in a short time by the strutting and chasing characteristic 



TABLE 7. 



A GENRRAIJZED BREEDING BEH W lOR PXTTERN COVERING ADULT 

 MALE RUFFED GROUSE IN CAPTIVITY COMPILED FROM A STUDY 

 OF 78 INDIVIDUXL PATTERNS 



8 A.M. 

 5 P.M. 



May 



_L 



10 



11 



IS 



16 



17 



18 



19 



20 



21 



22 



23 



23 



StruttiiiK 



Hfiad-twilchinjr C = Chasing 



Activity not cliuracleristic of breodinp pi'rioil 



of the third phase. If one charts for all the males the occurrence of each phase based on 

 characteristic behavior, there appears to be little tendency to pass through these more than 



once in a single season. 



A bird, of course, does not change from one phase to another overnight. During the 

 interval, which may last for a week or more, one finds the behavior characteristic of both 

 phases exhibited many times. Once the bird is well into a phase, however, except for strut- 

 ting, one does not commonly observe the behavior characteristic of the next stage until it is 

 approached. 



Perhaps the situation, as it seems to the authors, can be clarified by considering that male 

 grouse in ca])ti\itv normally are in a state of physiological readiness to mate during the latter 

 part of the first j)hase, throughout the second and the first part of the third phase. The act is 

 not normally carried to completion, however, unless the male is externally stimulated above a 

 point one might call the threshold of mating. 



