Social behavior in a non-pupping colony of Steller sea lions (Eumetopias jubata)
An ethogram of 22 behavior patterns is described. Larger and older sea lions (Eumetopias jubata) are dominant to smaller and younger ones. Males are more socially involved, and their behavior becomes more complex than that of females.Adult male and female behavior is less vigorous than that of subadult males. Territories where adult males and females are concentrated are more tranquil than areas where subadult males aggregate. Since females avoid areas of activity and harassment by sexually mature subadult males, they group in territories which act as refuges. This contributes to the spacial organization of the colony.The behavior of subadult males results in social disruption, whereas social stability is accommodated by adult males and females who are more stationary and so maintain prolonged social relationships.Non-pupping colonies are spacially organized similar to pupping colonies except for the relative proportion of age–sex classes. Socially, non-pupping colonies are less organized than pupping colonies. Social organization in E. jubata is promoted by the tranquil or energy-conserving behavior and ability of adults and inhibited by the behavior of subadult males.