is oven the collective noun? how cool! i know it's a Bazaar of Guillemots.
Oystercatchers, i tried to sneak up on them in North Berwick and only got fuzzy shots with a 300mm.
one thing i did with my camera was to set the meter zone for central, not full screen. i found that when snapping birds there was a chance of lots of water/sky in the shot and it tended to make it underexposed. of course, now i get over exposed shots - hey ho. the big lens is a real pig to focus as it's a narrow aperture.
the really big lenses are ok, but i'd get worried having one as tall as me, as some seem to be. the 500mm mirror is still fairly compact. i figure i'm taking the shots for me and i don't care if i can't get the eyelashes on a robin from 10 miles away. i'd rather go out and enjoy the wildlife and take some snaps for memories and pleasure. i've seen shots taken through scopes - you'd have been hard pushed to actually see the bird in real life, yet they had a close-up. nice, but you can hardly go for a nice walk and carry your camera in your hand - you'd need a 4x4 to lug the gear!
anyway... ramble over.
great shots. you have captured the fauna and flora. it's nice to see where these animals live as well as their eye colour.