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Subject: White Wagtail ocularis 白鶺鴒 [Print This Page]
Author: Paux    Time: 10/01/2021 16:27     Subject: White Wagtail ocularis 白鶺鴒

09.01.2021
Shek Kong Catchment



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Author: Roman    Time: 10/01/2021 19:46

This is likely M.a.lugens rather than ocularis
Author: happyman    Time: 11/01/2021 11:48

Is that M. a. lugens comes with a black back while M. a. ocularis comes with a grey back?
Author: cgeoff    Time: 11/01/2021 15:08

Why's that Roman?
Author: Roman    Time: 11/01/2021 15:21

Quote:
Original posted by cgeoff at 11/01/2021 15:08
Why's that Roman?
From the pics we can see the thick rear part of eye strip, and the whitish greater converts.

[ Last edited by Roman at 11/01/2021 15:22 ]
Author: Paux    Time: 11/01/2021 23:37

Roman, thank you for your comments. I have gone through a couple of relevant articles found on the net. As the bird in question was probably a 1st year juvenile, it will be even more difficult to ID; a juv. ocularis looks very alike a juv. lugens. For the time being, I am inclined to think this was a White Wagtail ocularis as the greater coverts were darker than those of a lugens. Nevertheless, more expert opinions will be much appreciated as I am just an ordinary birder.
Author: happyman    Time: 12/01/2021 07:42

Not sure if the diagram below would do any help?

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Author: ajohn    Time: 5/02/2021 10:32

I'm sure this is ocularis rather than lugens.
- I don't think the eyestripe broadens as much as expected for lugens, and is actually quite narrow still where it meets the black nape. The eyestripe on ocularis is normally slightly wider behind the eye than in front, but no to the same extent as lugens and without showing the 'step' in broadness that lugens commonly shows.
- The upperparts are very pale grey - although first year lugens can have grey upperparts, they are not usually this pale. On pale lugens the crown would not normally be black as it is on this bird.  
- Importantly, the rump is also grey with only the centres of the longest upper tail coverts black - lugens should show more black on the rump than this.
- The greater coverts have white fringes but this is typical of ocularis. I would expect lugens to show more white than this in the greater coverts, but also in the median coverts (usually mostly white with just a narrow dark streak on the shaft) and tertials, and possibly even the primaries and secondaries. The lesser coverts would normally be darker than this on a black-backed subspecies like lugens, at least with black feather centres and often mostly black.
Author: Roman    Time: 5/02/2021 11:43

Quote:
Original posted by ajohn at 5/02/2021 10:32
I'm sure this is ocularis rather than lugens.
- I don't think the eyestripe broadens as much as expected for lugens, and is actually quite narrow still where it meets the black nape. The eyestripe on  ...
Thanks John, This is helpful again.
I thought I understand this two race but seems I am definitely wrong on that bird, even I have seen this individual and watching it careful, this is important to check it part by part.
Could you check the below bird at Santin I was identified as lugens previously, I think it still match the points after your advice, thanks.

[ Last edited by Roman at 5/02/2021 11:46 ]

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Author: Paux    Time: 6/02/2021 12:14

John, thank you for your very detailed analysis.
Author: ajohn    Time: 14/02/2021 14:30

Quote:
Original posted by Roman at 5/02/2021 11:43

Thanks John, This is helpful again.
I thought I understand this two race but seems I am definitely wrong on that bird, even I have seen this individual and watching it careful, this is important to c ...
This bird also looks like ocularis to me - typical head pattern, pale grey back, grey lesser coverts, not much white in primaries/secondaries. The white in the greater & median coverts is a bit more extensive than on the first post, but you can see the dark centres to the GC and this pattern is well within range for ocularis.
Author: Roman    Time: 14/02/2021 15:06

Quote:
Original posted by ajohn at 14/02/2021 14:30


This bird also looks like ocularis to me - typical head pattern, pale grey back, grey lesser coverts, not much white in primaries/secondaries. The white in the greater & median coverts is a bit more ...
Thanks, though lugens are overlooked in HK, but in fact seems it's over reported by me, I am afraid I never seen lugens in HK.



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