General description of 3cy heuglini in March in Bahrain:

Primary moult completed, in that all primaries are second generation or older, and no bird showed a retained P10. At least one 3cy bird had P10 still growing. The primaries are black, without white tips and all birds lacked a mirror on P10. However, maybe a small mirror on P10 is possible.

Head shape is not rounded and pigeon-like as in many (female) barabensis, rather square or blocky, with a sloped forehead which smoothly continues onto the bill, reminiscent of cachinnans. The thumbprint in front of the eye (common in barabensis) is not obvious in heuglini, the facial expression is dominated by the strong eyebrown, creating a rather vicious look, not unlike West-European Herring Gulls.

Most 3cy birds have a white head with delicate neat streaking, concentrated in the lower neck but running down to the sides of the breast and over most the area behind and above the eye. The bill is yellow or pink. Sometimes there is already some red at the gonydeal angle, but this can be obscured by the black markings. Iris is brown-yellow to green or amber.

Upper parts in 3cy heuglini: most of the scapulars and mantle are moulted to grey, adult-like feathers. Some brown greater and lesser coverts may be present, especially in the outer greater coverts.

Tail: a broad black tail-band. The white tips of the old feathers are worn away. we did not come across enough birds to get in-depth insight in the variation of the tail pattern in 3cy heuglini.-

Legs flesh-coloured, pink or pale yellow.