AGE – BEST CRITERIA:

Both 1cy and 2cy+ slowly moult all RR as part of their pre-br moult, typically from Oct to Dec in males, while females often carry some juv RR into spring. Presence of juv RR is always diagnostic of a 1cy bird. Presence or absence of juv RR is the most reliable ageing character from summer to mid-Oct for males and to Feb for females, and a strong supplementary character for still some weeks after that. In 1cy males at least one juv R is often present well into Nov. Cloacal examination (in the case of males) and length of T2 are also very reliable. Other criteria seem to be subject to large variation.

1cy:

• Juv RR are very distinctive, ending in a V-shaped notch with the feather shaft exposed. This is because fledgeling ducks grow a downy tip to the RR, and as the tip falls off it leaves behind this pattern. They are also narrow, brownish and often quite worn. Females are slower to moult the tail than males, so juv RR are often found well into spring. It must always be kept in mind that, as with any bird, some RR or even whole tails can be lost or randomly replaced.
• In young males, penis very reduced until at least Dec. Please note that cloacal examination requires careful handling and practice.
• T2 short. If T2 is shorter than tip of P7 when wing is semi-folded in natural position, the bird is a safe 1cy. If between P7 and P6, ageing based on this character is not recommended. Keep in mind that P1 is extremely reduced in ducks. Young males typically show juv TT until Nov-Dec, and females until Mar.
• Other characters (design of T1, TC, shape of GC, fringing in LC and MC, shape of PP and PC and spotting in bill) are discussed in the images below. Beware that these characters are subject to much variation and should not be used in isolation.

2cy+:

• Ad RR end in a point, are broad and grey. Sometimes two ad generations can be found (which is diagnostic of an ad bird) by judging a difference in coloration and wear. Finding growing RR is also useful. Females are slower to moult the tail than males, so two generations are often present well into spring.
• In ad males, penis quite long and wide in diameter. Please note that cloacal examination requires careful handling and practice.
• T2 long. If T2 is longer than the tip of P6 when wing is semi-folded in natural position, the bird is a safe 2cy+ until Nov-Dec (for males) or Mar (females). After these dates, most 1cy will show freshly moulted post-juv  TT which can be as long as in ad.
• Other characters (design of T1, TC, shape of GC, fringing in LC and MC, shape of PP and PC and spotting in bill) are discussed in the images below. Beware that these characters are subject to much variation and should not be used in isolation.