The British Ornithologists' Union Taxonomy subcommittee recently released their annual recommendations report for 2011 (.pdf), and while the most of what goes on in the birding scene in Great Britain operates independent of those of us here in North America, there were a couple splits that could be predictive of potential new species in the AOU and ABA areas.
First though, the BOU mirrored the recent decision by the AOU to separate the Palearctic Kentish Plover, Charadrius alexandrinus, and its Nearctic counterpart, Snowy Plover, Charadrius nivosus, but they didn't stop there. Two additional members of order Charadriiformes got pared off as well.
Whimbrel, Numenius phaeopus, was also split along hemispheric lines, with the white-rumped Old World group officially becoming Eurasian Whimbrel and retaining the scientific name, and our dark-rumped North American birds regaining the storied name, Hudsonian Whimbrel, Numenius hudsonicus. If accepted by the AOU, this would represent a new species for North America, as 'Eurasian' Whimbrels are regularly noted on the east coast and generally offer little in the way of identification pitfalls.
More interesting is the split of Sandwich Tern, Thalasseus sandvicensis, into the Eurasian population that retains the name famously referring to the English town rather than the lunchtime treat, and the North American acuflavida and eurygnatha subspecies, to now be known, according to the BOU, as Cabot's Tern.
Recent molecular analyses suggests that the New World population, Cabot's Tern, is actually more closely allied with Elegant Tern than the nominate subspecies, and therefore the split is in order. Additionally, differences were noted in all plumages between North American and Eurasian birds; differences that European birders are no doubt poring over in the wake of this decision. North American birders would do well to bone up similarly, as Sandwich Tern (Eurasian Sandwich Tern now?) is a likely stray to our shores.
It remains to be seen whether the AOU tackles these splits as well, as they seem to be a little more conservative when it comes to Old World/New World splits. They'll no doubt consider them in upcoming years, and the recent separation of Common Moorhen and Snowy Plover may well portend a wave of such taxonomic changes, in which case this BOU decision is only the beginning and birders might want to bank their armchair ticks in preparation.