GROUP ORGANIZATION 193 



order. There is some suggestion from the effect of 

 broodiness in hens and from observations on the 

 nesting cycle in canaries that there may be elements 

 of control by hormones. This lead is being investi- 

 gated actively at present, but I have no definite re- 

 sults to report. (6) 



Some of the complications in determining the fac- 

 tors that make for dominance are shown by the pre- 

 liminary summary which Mr. Shoemaker has given 

 me of his studies on the social hierarchy in canaries. 

 The space available for the caged flock is a matter 

 of importance. When confined in relatively small 

 space, the social order becomes more simple and 

 definite and there is no complication over the ques- 

 tion of territorial rights. With more space, as for 

 example in a large flight cage, individual territories 

 tend to become established in which the particular 

 bird is supreme even though it ranks low in the 

 neutral ground around the bath bowls, the feeding 

 places, or regions where nesting material is stored. 



When canaries are allowed to mate and small 

 nesting cages are supplied around the walls of the 

 flight cage, each individual male is master in its own 

 nest cage and controls more or less territory around 

 the cage entrance. Under these conditions even the 

 birds lowest in the social order dominate in some 

 restricted space about their nest. 



