There are 5.6 of these Deer now- the only ones in UK. This, the biggest male and so the 'master' buck, was in full rut, very active and following one particular doe all the time, trying to mate her and also from time to time chasing the other males away (he's having a well-earned rest here...) I heard his rutting call too-very similar to the Common Fallow's 'groaning' call but more drawn out and not so repetative.