Sunday, June 13, 2010

DUCK ID







Only got 3 more shots.
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3 comments:

heavy birder said...

That's a better photo, changed my mind, eclipes male Mandarin ?

8:25 pm
David Tattersley said...

I would suggest on probability that the bird in question is a juvenile Mandarin Duck as I came across a family of Mandarin Duck (male, female and 2 juveniles) a few days ago on the River Calder outside of the Calderdale Area.

The male Mandarin (which sometimes rejoins the female and juveniles after they fledge) was not in 'eclipse' plumage and the juveniles I observed were identical to the one in Mike's photo.

The bird has the 'jizz' of a juvenile and the fact that it is 'out in the open' perched on a weir is not consistent with my local experience of an adult Mandarin along the River Calder which on the whole tend to be rather wary and usually take flight or remain motionless in the cover of vegetation when under observation.

I am not familiar with the plumage of Wood Duck in our area but I am aware of at least two male Mandarin Duck on the River Calder in the Calderdale Area during spring although I personally did not see a female.

This might be surprising to some observers as in some areas they are very confiding, however locally I find that they they can be very elusive and easily overlooked therefore on balance, as no one to my knowledge has sighted a Wood Duck in recent times I think the odds given the location and plumage characteristics are heavily stacked in favour of a juvenile Mandarin Duck.

9:45 pm
Steve Cummings said...

I'll go for an eclipse male Mandarin

Eye Spectacles Wide as Wood Duck
Eye colour Black as Mandarin
Head colour/contrast pale/slight as Mandarin. Wood Duck pictures appear darker
Bill Colour Orange lower mandible, Dark tip, Pale nail as Mandarin
Crest lacking juvenile or eclipse
Cheek marks absent suggesting not male wood duck juv/ecl but not conclusive
White around bill base difficult to discern from photo
Breast streaking Contrast of streaking suggests Mandarin
Vinous “nipple patches” These, and a similar mark at the base of the neck appear to be remnants of male summer plumage (Mandarin or Wood Duck)
Vertical flank/breast stripes (2 of) 1st is black , 2nd is black/white/black suggesting eclipse Mandarin
Wing coverts dull brown = mandarin, glossy = wood duck
Flank spotting large round pale spots suggest mandarin
Leg length long = mandarin or short = wood duck – you decide
Time of year 12th June Moult takes place June – September

The vertical flank markings and the vinous patches point to it being an eclipse male. Time of year is also right for this to be the case. I would not expect a juvenile to have these markings at this time of year. The additional photos point towards a pale rather than a black nail. This, and all the other features above, with the exception of the broad spectacles, point to Mandarin. Having seen Mandarin pair with Mallard, and recognising the dubious origins of our feral Mandarins one cannot rule out the possibility of this specimen having a bit of Wood Duck in it. .

On a slightly different note, Mandarin ducks have been known to undergo sex changes when they get infected ovaries, causing the ovaries to turn into testes. They develop male plumage but with female coloration and become fully functioning males!

http://www.google.co.uk/imgres?imgurl=http://www.utahbirds.org/featarts/2004/MandarinDuckTS4.jpg&imgref

7:53 pm

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