Hello Con,
Whilst I won't be absolute, as I don't know all details for all ducks but it is
quite typical of ducks (some / several / most /all species - I don't know) to
moult all their flight feathers at the same time, making them flightless for a
while. Doing it all at once also makes the moult period shorter than the usual
progressive moult of most birds. I was just reading about that in HANZAB today.
The photo does show this for primary and secondary wing feathers as well as
other areas (the alula or thumb and just general).
Philip
-----Original Message-----
From: Con Boekel
Sent: Sunday, 7 February 2016 6:18 PM
To: canberrabirds chatline
Subject: Further to the moulting Black Duck
Earlier today I posted an image of a Black Duck which appeared to be regrowing
feathers after moulting - probably primary and secondary wing feathers. The
image attached is of a bird that was hanging around with the moulting duck. It
too appears to be heavily into moult. The size of the wing seems to me to
indicate that this particular individual is flightless. I don't really know
whether that is correct, or not.
I have heard of some species moulting all their feathers at once and being
flightless while doing so but I must admit it had never occurred to me that
Black Ducks might spend part of their year being unable to fly.
regards
Con
Black Duck
JWNR
7 February 2016
Con Boekel.
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