After the pre-breeding moult, all birds can be sexed based on the presence on white on outer PP and RR. Females may show relatively large pale buff markings where males show a pure white speculum in wing and on tips of outer tail feathers. Birds with juvenile PP and RR are probably not possible to safely sex. However, Roselaar (in Cramp 1985) describes birds having small whitish markings on outer PP, where adult males are white, together with rather pale, unmarked tips of outer RR as males. We have recognised the pattern described but do not know if these characters have been firmly tested.
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