Hendrix

MPNR 9/12/07

黑海番鴨  Black Scoter Female ?











as it got no color on front tip of bill , the bill shape, the up tail .

I think it is Black Scoter  after look this pages:

http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/Black_Scoter.html

http://www.npwrc.usgs.gov/resource/birds/duckplum/bscoter.htm

for Red-crested Pochard :

http://bedsbirds.blogspot.com/2007/01/red-crested-pochard.html

http://www.chasewater.org.uk/diarymonths/2007/July2007.htm

tmichael

And I think you are right, Hendrix. In fact I know you are, because of the flight shots.

Just for the record I didn't see it in flight or flapping its wings - in which case alarm bells would certainly have rung - and juv Red-crested Pochard has an all-dark bill like this bird, though a different shape.

Also as Mullarney et al (Collins Bird Guide) put it juv/female R-c Pochard is "like a large pale Common [Black]  Scoter". And I did say to another observer the bill shape and long, 'stiff' tail looked odd.

Oh well, it was only a first for HK which I misidentified!

Mike Turnbull.

PS Mullarney et al also suggest separating them on the basis of habitat!

Hendrix

thanks Mike .


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BTW , there still many dog around 16/17 , 20/21  :shock:

WWF Mai Po

Hi Mike,

If its any consolation I too had it down as a possible juv./female Red-crested Pochard even after looking through the guide books. I did however see the bird thrusting its head (as shown in Hendrix Photo 2) on several occasions which should have helped identify it. I made a few sketches in my bird note book just in case, but luckily Hendrix came along with his camera around 08:30.

I first picked it up at 06:50 this morning, but can say for sure it has not been in with the Tufted Duck flock since Tuesday 4th December because I've been doing dawn bird counts from the canvas hide every day since then. I'll check again tomorrow.

Great photos Hendrix.

Bena Smith
WWF Reserve Officer

kmike

A fantastic find - wish I could have come to see it today!

Cheers
Mike K

ajohn

I think the excellent series of photos taken by Hendrix prove the ID of this bird as Black Scoter. It seems to be a first-winter bird, possibly male (based on the darker feathers starting to show on the underparts and face)

The bird was not relocated this morning, but may still be around with the Tufted Duck flock, but can be surprisingly difficult to pick out!

Just as well some of us were paying attention to the ID, eh?

kmatthew

no sign of the scotter this afternoon...

calexander

What a tick for Hong Kong!!!
We saw a few last time in Hokkaido in 2003. We focused too much on the male ducks. Just a poor documentary photo here for your reference.

If God allows, may be there is a chance to have Scaly-sided Merganser in Hong Kong too!

ajohn

Since the discovery of this scoter last year, there has been some discussion about whether the bird can be safely identified as Black Scoter, and whether Common Scoter can be ruled out. The ID as Black Scoter (Melanitta americana) is based largely on range, as this is the form that breeds in eastern Siberia (and America) and winters in the Pacific (including northern China). Common scoter (Melanitta nigra) breeds to north-central Siberia and winters in Europe. The two were treated as one species until recently.

The debate for the HK bird is whether it is possible to seperate female/immature Common and Black Scoter in the field. This issue is addressed in the recent book 'Frontiers of Birding' by Martin Garner, who suggests that the two can be separated. Checking internet photos I agree. Note that the following is based mostly on photos - I have limited experience of common scoter and have only seen one black before the HK bird. I am basing ID on Hendrix's photos and photos by Martin Hale at: http://orientalbirdimages.org/se ... lt&Bird_ID=2800

The book suggests the two species can be separated by the following charaters typical of black:

• - Lumpier bill, often with slightly swollen base and prominent hooked/arched nail. The HK bird has a very prominent nail (bill tip). The bill is not as lumpy as some Black scoter but is fairly short and deep-based, not long and triangular as on Common Scoter.
  
• - Typically steeper forehead and squarer head shape.  HK bird has a rather square-looking head (see Hendrix first photo). Common seems to show a rounder head, peaking just behind the eye.
  
• - More dark patterning on sides of nape. Although the HK bird shows the dark pattern narrowing to the base of the nape, this seems to be in the range of Black. Checking internet images, the dark cap on common seems to be more horizontal, often reaching the top of the bill, level through the eye and then back to the nape. The HK bird shows a gentler curve from the bottom of the bill and fairly broad on the nape.
  
• - Dark cap may end as a squared-off or broad rounded line on the nape, not tapered as in Common. The HK bird seems to show a squared-off end to the dark cap (see second photo of bird head-flapping), although the cap does narrow to the base of the nape. The end of the cap on Common often seems to almost meet across the back of the nape.
  
• - 10% of adult females show extensive yellow on bill. No yellow on bill of HK bird, but this does not rule out either species, especially on a first-winter female (which I think is the case for the HK bird)
  
• - Cheeks tend to be cleaner with a less obvious dark vertical cheek mark.  Some of Hendrix's photos show a hint of the dark cheek-mark, but this is not obvious. This seems to be a variable feature in both species, which may depend on light conditions. The HK bird is probably in the range of variation for either species.
  

Other features mentioned in the book (based on observations of males, but probably also applicable to females) are a tendency for black to sit higher in the water and cock the tail more often. The tail may also be shorter. In these respects, the HK bird fits better with Black Scoter.

Overall, I think the characters of the HK bird fit better for Black Scoter than Common. This is also the more likely species based on range. I would be happy to hear comments from others, and any additional photos may help establish ID (even, for example, photos from the rear which show the exact nape pattern). I think the bird should be possible to ID - it would certainly be a shame to dismiss this as 'Scoter sp.' unnecessarily.

tmichael

Thanks for this very illuminating note John.

Next time I find one I'll know exactly what I'm looking for, once I've eliminated one or two other merely remotely similar species!

Mike Turnbull

wgeoff

Black Scoter is common in Japan and Korea, regular in north and east China and only a few hundred miles out of range in Hong Kong.
Common Scoter is more than 5000 miles out of range in the opposite direction to its normal flight and has never previously been recorded in the Pacific or North America.
As this bird is one or the other, and nothing else, Black Scoter is so much more likely than Common Scoter that it seems unnecessary to debate which it is. We regularly record species in Hong Kong with a distribution like Black Scoter, but never like Common Scoter.

Looking through the images of Common Scoter on the Birdguides website, two features seem to regularly occur with female Common Scoter. One is a distinct dark cheek stripe stretching up from the chin towards the cap. The second is that the dark cap does not go all the way down the nape but ends around the middle of the nape. This is caused in a side-on view by the dark cap gradually narrowing to a point as it goes down the nape. The Mai Po bird does not appear to show either of these features. Unfortunately, I cannot reproduce the photos here but Martin Garner's two diagrams show the differences he suggests between the two species



As John says, from Hendrix's photos, the bird is closer to Black Scoter. There is no evidence to suggest it may be a Common Scoter.

Taking distribution and these features together, it is surely stretching possibilities too far to suggest this could be a Common Scoter. There has to be a point at which you say, no, Common Scoter is so unlikely that I can ignore it, even for a first record.

[ Last edited by wgeoff at 5/10/2008 08:48 ]