Ruminant species that have been successfully domesticated are invariably social species that are comfortable living in groups and that have a hierarchical social structure.
Red deer and wapiti are no exception to this; they exhibit a strong social hierarchy structured around highly seasonal annual breeding patterns.
This social hierarchy, however, is characterised in natural populations by the separation of mature males and females at all times of the year except the rut (mating).
More resources
The book by T.H.Clutton-Brock, F.E.Guinness & S.D.Albon (1982) ‘Red Deer: Behaviour and Ecology of Two Sexes’ (University of Chicago Press) is a very good account of social behaviour of wild red deer on the Isle of Rhum, Scotland.