One may wonder what profit there is in comparing the social adaptations of organisms as diverse as birds and ungulates. Yet such a comparison indicates that useful insights into adaptive strategies may be gained not despite but because of their great differences. It shows that old phylogenetic constraints greatly affect social adaptations; that in ungulates as in birds, social and ecological specialization appear to run parallel; that environmental extremes tend to produce grotesque giants or monomorphic forms as the terminal product of social and ecological evolution; that social evolution proceeds from stable to unstable habitats, warm to cold, moist to dry, low latitude and altitude to high latitude and altitude; that therefore zoogeographic patterns are closely related to social and ecological specialization within a given family; and that the evolution of sexual dimorphism, weapons, defences, and display organs parallels in birds the patterns seen in ungulates and is probably subject to the same explanations. In short, a comparison of sociobiology in birds and ungulates reveals unifying factors by explaining attributes of birds first explained in ungulates, and vice versa. The present paper is a limited attempt to point out explanations apparently applicable both to bird and to ungulate societies.