In reply to BusyLizzie:
Ahh, you lucky thing! Camping or Landmark Trust?
My (current) favourite is the Gannet. Gorgeous colouring, and such a dramatic sight to see them diving into the sea. Look out (or listen out) for Peregrines too. Make sure you take some binoculars!
Agree with what someone else has said - do the letterboxing, it's a great game and a great way to see the island just take it slowly and enjoy it rather than rushing from pillar to post to get it done (unless that's your thing in which case crack on!). I haven't completed yet and have been chipping away for about four trips, it's a lovely thing to come back to. Good luck with Earthquake : )
Again agree with someone else about the seals, you can spend an age watching them. If you go to the old landing stage for the North Light at high tide there is a lovely zawn where if you are lucky you can watch them cavorting underwater, it looks a bit of a sketchy approach but just follow the old rail tracks and don't hang on to the rotted handrails and it's fine.
Enjoy!