On 28th May 2010 Dato’ Dr Amar-Singh HSS photographed the Red-wattled Lapwing (Vanellus indicus atronuchalis) in flight (below left) in Ipoh, in the Malayasian state of Perak. The enlarged image on the right shows part of the right wing with the primary flight feathers numbered P1-10 and the a portion of the secondaries numbered S1-6.
Dr David R Wells commented: “Yes, lapwing is moulting primaries 1-3 (7 old ones still there). When researching for Vol 1 of my book I only found one instance of wing-moult. This picture of yours fits very neatly in terms of seasonal timing…”
Wang Luan Keng made the following observations on the moulting: “From what I can see, P1 is a new feather or almost fully grown feather. P2 is not visible from the photo and most probably still a pin, while P3 is half grown. This is a rather interesting case as usually birds (especially large birds) will only grow one feather (on each wing) at a time, as moulting is an energetic-demanding process. Moulting 2-3 simultaneous feathers at the same time would also create a large gap on the wing, which can be aerodynamically inefficient. Although the lapwing is a medium-sized bird, no doubt some of the above concerns of moulting would still apply.
“It is also interesting that the moulting sequence is not in a linear series. In general, most birds would moult from P1 to P10 in a sequential manner but in this particular bird, somehow P3 has gone ahead of P2. Another interesting feature on the wing – although the outermost two feathers (P9 and P10) are old feathers, they are somehow not worn, as compared to the rest of the old feathers (P4-8), which are very worn out and torn. I wonder what could have caused such serious wear and tear during the lifespan of these feathers.”