Vagrants 

Whilst updating my website recently I came across the fact that a Great Black Hawk was voted "Number one craziest vagrant of 2018" by the ABA. This led me to thinking about other unexpected records, of which the UK, due to its geographical location, has more than its fair share. None more so than the moribund White Tern recently, but many unexpected seabirds have turned up in the last decade- Boobies, Albatrosses (other than Black-browed), Soft-plumaged Petrel, White-chinned Petrel etc. With climate change and weather patterns altering virtually no pelagic species is totally unexpected, plus we knew little of some species movements before satellite tracking, so birds may have been dismissed as "impossible". However, many of these are untwitchable, although a lot of people have added one or two Boobies to their list. Having seen plenty whilst travelling I didn't bother, but on driving north just after a long-staying  Brown Booby had moved on I stopped at a B and B. The thing flew past the headland about 200yds away just before I finished breakfast! Brown Boobies seem to be reported annually now, although some may well be immature gannets. But..... are they Brown, or are birds in the south west Cocos Boobies, (Sula brewsteri)?, which was split a couple of years ago. It's possible, given that Black-capped Petrel has occurred here, and several species from the west coast of America. The same thing applies to Tropicbirds, the only one recorded is Red-billed, but it is likely that some, if not all records, come from the Red Sea (subspecies indicus) which may one day be split as Arabian Tropicbird.

The most unexpected seabird vagrants must be some of the auks, or so we thought, until we were on the Isle of Wight ferry back in 1990 when someone said "what the F****'s an Ancient Murrelet? We now all know, and this was followed by the famous Long-billed Murrelet in 2006, which was even more unexpected. There couldn't have been many people at Dawlish for whom it wasn't a world tick, given my penchant for seabirds I was one. It seems that many auks fly long distances despite their short wings, and Pacific auklets have been recorded inland and on the East coast. Did the Long-billed fly across from Asia via a "great" circle route, or did it stage across the USA? Whatever, I think we can assume that Japanese Murrelet is unexpected, but you never know!

 People have long tried to guess the next new bird or the oldest "blocker", but really they're on a hiding to nothing. Many people thought that Varied Thrush would never occur here, and a leucistic type is so rare that many people never accepted the Cornish bird to be anything other than a cagebird. But a normally coloured one turned up, albeit half a century later. Many birds which were once unexpected have become just the opposite -you wouldn't have put money on Black-shouldered Kite when I started birding, and we thought another record of Pallid Harrier after the 1953 bird was just a pipe-dream. Dalmatian Pelican, Lammergeier, Egyptian Vulture were all unexpected not so long ago, although re-introduction programs have been partly responsible. Baikal Teal was once unexpected and records were removed from the British list because it was thought to be so rare, that is, until a wintering flock of 10,000 was discovered in south-east Asia. 

I personally think Macqueen's Bustard is the least likely species to turn up again, closely followed by Pallas's Sandgrouse. Pallas's Reed Bunting and White-winged Lark are unlikely, but certainly possible visitors, whilst Red-breasted Nuthatch is almost probable. Wood Thrush could easily turn up again, but it's taking its time! Blue-winged and Golden-winged Warblers, whilst possible, are falling in numbers in the USA, partly due to hybridisation, so that's anyone's guess. Obviously thousands of species of landbirds will never turn up for various reasons, Rhea, Emu, Hummingbirds etc. but there must still be quite a number which are unexpected, as well as many which have been expected for ages but missed us, such as Willet. There can be no reasoned argument as to the next one, given the term unexpected, but I suppose I'll hazard a few complete guesses just for fun. How about Spoon-billed Sandpiper, Horned Puffin, Western Tanager, or Grey Bunting. Don't hold your breath!