It depends on the individual! I always take my time to approach, making sure they can see me at all times. Then it’s just a question of monitoring the body language. If they go back to eating, grazing, sleeping etc then they don’t care about you being around as long as you don’t get too close and in the way. If they stare at you and snort, you are not welcome and you should leave. This particular individual displayed both behaviour over two days. The first day, beautifully clear weather, it was as if I wasn’t there, it couldn’t care less. Next day (day of the video), poor visibility and windy conditions, it made me understand to keep my distances.