Alison that is the type of behavior I observed while volunteering during the making of the (still to be screened) BBC documentary at Mulligans Flat several years back. You get a female (in front) followed by a number of males in a group, sometimes following closely but often just feeding together. I have seen a larger male leave the group and go some distance off to feed or drink (50 M) before returning again. I would confident to call that a train. Derek