The Social Hierarchy in Ring Doves. II. The Effect of Treatment with Testosterone Propionate

Social organization has been described in flocks of many species of birds both wild and caged. Schjelderup-Ebbe ('24, '31) reported in more than fifty species a type of hierarchy which he designated as a peck-order. Subsequent investigation by others has confirmed his observations with relation to the domestic chicken (Masure and Allee, '34a; Murchison, '35). In the case of pigeons and shell parrakeets, Masure and Allee ('34b) reported a social order based upon rather than peck-right, that is, upon a dominance established after many conflicts rather than upon an initial combat. Shoemaker ('39a) and Bennett ('39), in flocks of canaries and of ring doves respectively, likewise found peckdominance to be characteristic of the social organization in caged flocks of these birds. Others who have observed hierarchies in bird flocks, based upon dominance in some form, are Lorenz ('35) in jackdaws, geese, and certain other birds, both in wild and artificial associations, and Noble, Wurm, and Schmidt ('38) in American black crowned night herons. The question arises as to what factors underly the social organization in a flock of birds. Schjelderup-Ebbe ('35) directed attention to a number of conditions which he believed to be of some importance in this matter. Among them were health, season, sex, age, relative strength and fatigue. Certain of these same conditions have been recognized by other investigators. Allee, referring to the do-