Can I Count It As A Find?

Quick answer: No! But let me explain...
When news of a female Red-backed Shrike at Holkham appeared it took me a while (well 10 min!) to decide to go for it. I arrived at the Washington Hide just before 11 am (I cycled down before you ask!) There were only two people in the hide and they hadn't seen the Shrike. However, whilst searching, I kept hearing bird song of varying variety(!) I mentioned it to the others, but only one heard something interesting. I mentioned the mimicry and Marsh Warbler was mentioned in passing! Unfortunately, it stopped singing as a couple of other birders arrived. 1/2 hour later there was no further sound, so I resigned it to a mimicking Reed Warbler (there was one singing nearby) and decided to go further a field to look for the Shrike! At 1 pm the pager went off the say a Marsh Warbler was singing just west of the hide at 12.55 - bit surprised I didn't get a phone call first. I cycled back quickly and after a few minutes the bird was heard and even seen briefly. The Red-backed Shrike was relocated by the original finders (who also identified the Warbler - thanks guys) so we went to see this, showing well, and returned to the Marsh Warbler. The bird seemed to have a small circuit, singing briefly and showing even more so. Storm approach and we left before the rain (and a picture!)

Marsh Warbler. Okay, it's not in there, but it was!