What about European Curlew (arquata), Oriental Curlew (orientalis) and Steppe Curlew (suschkini)?

Due to gradual changes in plumage and measurements across the distributional of Eurasian Curlew, it is at best very difficult to identify out of range subspecies such as the eastern orientalis race, breeding east of the Urals, and suschkini breeding in steppe regions of southern Russia and Kazakhstan.

Nevertheless, on walking along the southern shore of Anholt on October 5, 2013 I flushed a 1cy Curlew which called for attention due its flashing white axillaries and underwing coverts. I grabbed for my camera and as it made a quick turn and passed nearby me I shoot a series of flight shots.

The bird is surely striking with its white underwing coverts, unmarked white axillaries and sparly marked flanks, but the amount of dark bars and the off-white ground colour to the tail could indicate that it may fit in among western-type birds with the least marked underwing coverts and flanks.

Nominate arquata and orientalis are western and eastern extremes respectively of continuous cline of increasing bill and tarsus length, less heavy marking, and paler ground-colour towards east. No sharp boundary between these extremes. Nominate arquata from western Europe typically have short bill and tarsus, rather broad streaks on upperparts and chest, back and rump usually streaked, belly and uppertail coverts often marked with black blobs, flanks distinctly barred and often with large dark blobs, axillaries barred and often with black subterminal blob, and underwing coverts partly barred or spotted, especially primary coverts.

Typical orientalis from eastern part of range has longer bill and tarsus; narrower and less deep black streaks on upper- and underparts, and flanks and tail coverts less heavily barred and usually lacking black blobs; belly, lower back, upper rump, and underwing almost immaculately white; tail with fewer and narrower bars; axillaries white, a few with thin dusky subterminal shaft-streak at most.

Marks in juveniles of both races relatively narrower, body and axillaries appearing paler; in nominate arquata, bars on axillaries often broken or forming rows of dots only. If trying racial recognition, it is thus important to account for age differences.

With this amount of dark bars and off-white ground colour in the tail, this may just fit in among western-type birds with the least marked underwing coverts and flanks...