I didn't see this individual except in flight (so obviously couldn't count it, but well done Jeremy!)
A look at the top of the Sparrow's nest revealed up to 30 normal Long-tails, a briefly confiding male Blackcap, a fine Treecreeper (a rare sight in the Parks these days) and a Chiff- chaff and several Siskin heard and a Brambling heard too, flying over.
Arnold's walk revealed up to 100 long- tails, plus Rob Wil and Andrew E amongst other birders.
Retracing my steps following a call from Rob stating the warbler had been seen again, I walked back along Flycatcher alley, very briefly saw the Pallas' warbler in flight (a small olive-green warbler with yellow supercilia and wing- bars, white underparts) fly to the sycamores just east of the Pines on the Northern end of the bank behind the Oval. It disappeared after that. Walking further north along the North Denes, having seen Chris M, Peter N, Roy & Ruth H. OFB shouted "They're here!' and I ran back 30 yards and a group of Long- tailed Tits flew over the Pallas' area and into bushes along the bank and they included one then another absolutely stunning 2 white- headed Northern Long- Tailed Tits, absolutely stunning birds. One perched up well at the top of a hawthorne bush with a couple of normal Long- tails and stood out like a white beacon. before sadly, it flew a fair way north last seen fling over Links' road.
A female Kestrel flew past several times and perched at the end of the shelter belt briefly.
A female Sparrowhawk whizzed along the cliff.
Further searching revealed up to 5 Chiff- Chaff and several 3 Goldcrest and around 5 reasonably confiding Jays and behind the southern end of the Oval along the bank what may have been the Pallas' again, it was a small warbler (not Chiff or crest) flying very quickly at the back.
I briefly saw a grey warbler with a wing- bar in a tree, but too brief to specifically ID.