Among mammals there is usually an increased frequency of aggressive interactions when population density increases.Conducted at four zoos in southern India the study examined the effect of spatial crowding on social behaviour of three different species of ungulates, chital(Axis axis), black buck (Antilope cervicapra)and sambar (Cervus unicolor).Systematic behavioural observations were carried out both in winter and summer season between the various age-sex classes on the pattern of their behaviour across density.With incease in density, the mean aggression frequencies and severity of injuries...