Various predictions have been made about potential British firsts, and some have come to pass (Siberian Accentor being a notable recent example). My subject here is five possibilities which might be challenging. Three of them have been claimed already.
The five are: Pintail Snipe, Hume’s Short-toed Lark, Oriental Skylark, Plain Leaf Warbler and Red-headed Bunting. There are recordings of all five on the ‘Calls of Eastern Vagrants’ CD by Hannu Jannes, and the very useful Collins Bird Guide App has recordings of Pintail Snipe, Oriental Skylark and Red-headed Bunting.
There is a saying that exceptional records require exceptional proof. It is unlikely that any of the five would be accepted without photographic evidence, and in each case sound recordings would also be useful. The history of each of the five in Britain is:
Pintail Snipe – one was claimed on Stronsay on 1 April 2005 (’Stronsay’s Garden Birds’ pp. 293-294) but the bird in the photograph looks like a Common Snipe. For a previous discussion about this species, see https://rutlandbutterflies.wordpress.com/2013/09/18/pintail-snipe-an-overlooked-vagrant/
Hume’s Short-toed Lark – no British claims; one was in Israel in February 1986; a paper on the identification of this bird was published in Brit. Birds 83:262-272, July 1990
Oriental Skylark – one was claimed on Stronsay on 22 October – 16 November 1999 (‘Stronsay’s Garden Birds’ pp. 212-217); some elements of the description do suggest this species, but without supporting photographic evidence or recordings it is impossible to come to any firm conclusions
Plain Leaf Warbler – no British claims; one was in Sweden in October 1991; a paper on ‘Identification and status of the Plain Leaf Warbler’ was published in Sandgrouse 10: 107-109 (1988); although they look a bit like Siberian Chiffchaffs, the vocalisations are different
Red-headed Bunting – about 300 reports (including the formerly accepted first record from North Ronaldsay in June 1931) up to the EU ban on trade in wild birds in 2007, then none; the post-2007 picture is revealing, and contrasts with that of Black-headed Bunting which has continued to occur in small numbers; it is reasonable to conclude that Red-headed Bunting should not be expected to be more than a very rare vagrant
Any of these five has the potential to occur in Britain, so it might be worth reminding yourself of their key features…