Nice pictures Eleanor but your shutter speed was way too slow, for a focal length of 300 mm your shutter speed should be around 1/400. If the light is poor maybe think about increasing the ISO and that should help.
Agree with Dave, re shutter speed, the first shot is really nice the face of
the deer is great, when I scrolled down it looked better with less on the
bottom so maybe a slight crop would work. You have also managed to
avoid any ear tags so it looks really natural.
I can never find the deer whenever I go up there!!
Thanks for the comments, yeah the light was very poor that day and was wary of putting the ISO too high to avoid graininess. What ISO will this really become an issue to be concerned about?
Jenny, the deer are usually divided into two groups: the males mainly stay down at the footbal pitches, while the females and young are up the other end at the 15 acres.
Really depends on what camera your using but I think a grainy sharp image is much better than a soft image, I would say that ISO 800 should be fine at least.