Hoopoe and Serin - what a difference a day makes!

Yesterday I made the mistake of going birding to Holme and Titchwell,  Holme because it was devoid of any migrants and Titchwell it was full of numpties, plus there were hardly any birds either (c10 Long-tailed Ducks on the sea plus a couple of Spotted Redshanks on the marshes. The past few days have been so devoid of any migrant birds I did consider having the day at home (or even at work) and not bothering with going out into the field, but the change of wind (SW) and the forecast of rain made me think that there might be a few birds to be found on the east coast - I wasn't wrong!
I headed off to Horsey Gap, stopping just south of the mill to watch a Common Crane feeding in a roadside field. I parked up at Horsey and by the time I'd reached the east end of the approach road I'd already seen my first Willow Warbler and House Martin of the year. In addition to this, here were quite a few Meadow Pipits and Linnets going overhead, so bird were obviously on the move. I headed north towards the campsite and flushed a few migrant Song Thrushes from the coastal scrub. As I approached the campsite my attention was attracted to an unfamiliar metallic "zeeeeuk" above me. I raised my bins to see a small finch trailing a flock of Linnets. The bird called again and then headed off north. I watched it through my binoculars as it flew north over the campsite and then did a U-turn and headed back towards me with a single Linnet. It was obviously small than the Linnet and as it flew over me it called again. I was pretty confident by now that the bird was a Serin. I watched it fly south and out of view as it disappeared into a tiny speck in my binoculars. I made a few notes, phoned it out to RBA as a probable Serin and presumed that would be the end of it as a sighting. I'd not seen the bird well enough to get a description and as the bird wasn't giving the usual trilling flight call, decided I'd not seen/heard enough of the bird to be 100% sure of its identity and that it wouldn't get any further than my notebook as a probable Serin. I moved on north, through the dunes alongside the campsite. As I made my way over one of the dunes, a flock of Linnets flew up with some Starlings from the campsite, followed by an explosion of black-and-white as a Hoopoe flushed up from the border of the campsite and flew across the campsite - wicked! I sat and watched the Hoopoe for a few minutes and then put the news out on the pager. During a couple of calls with Tim Allwood, Tim said that it would be worth watching the campsite as the Serin might return to feed with the Linnets. I settled down in the dunes and scanned through the flock of about 40 Linnets. Nothing other than a couple of Goldfinches and a few Meadow Pipits. There was quite a bit of commuting going on with birds coming and going from the campsite, so I kept on watching and looking. Good job too, as just as Tim arrived so did the Serin. It flew in with a small group of Goldfinches and then fed with the finch flock for around 20 minutes, although the weather was turning rather nasty with rather heavy rain and strong winds. A few people arrived and we made our way to the finch flock as the rain had eased off. The Serin was a bit flighty, but gave good views in flight and gave it's usual quick, strung-together repetition of 3-4 call notes - "tri-li-li". It finally gained height and then headed off south, not to be seen again. There were a few other birds in the area, with a male Ring Ouzel at the pipe dump being the best of the rest.