We have tried to ask for help from several overseas birders who has much
experience on the MURRELET. And thanks to Geoff Welch's help,
we were able to have some helpful and interesting comments
from Nial Moor & Nick Lethaby of 'Birds Korea'.
Quote from Mr. Nial Moores in reply to Geoff Welch's email :
"....While I have lot of experience of Ancient, I have seen very few
Cresteds in recent years, and to be frank, I am not certain of the id of
this bird. I can fully understand why people believe that it could be a
Crested, based on bill colour and most especially on the apparent vestiges
of a crest (not something I have ever seen on Ancient). Perhaps this really
is enough to clinch the id?
However, there are several things that do worry me, a lot, (and others I
presume?), especially for a territory first..
1) The crest here is perhaps not where it should be on Crested? Crested
have long fine feathers going back from the fore-crown, not perhaps from
the bushy supercilia or from the upper nape (as apparently here). Could the
crest simply be a product of a very tatty plumage?
2) The bill. Although the bill looks long, this could perhaps be partly a
product of the extreme wear on this bird, exaggerating bill length? In
addition, while the bill appears blue, this could also PERHAPS be a
part-product of ill-health or light. We do very often see birds here with
greyish or grey bills anyway (not the bright, pale blue of Crested, and
certainly not the vivid pink of the images on the HK website!), and it is
hard to judge the bill tone well from these images (though the impression
is paler than you would expect in Ancient). It seems too that the bill
looks fairly blunt, shows a contrastingly pale tip perhaps, and also dark
on the lower mandible too. Several close up images of Crested eg on Google
Search show the bill to be long, slightly decurved, and rather fine-tipped,
with (in adults at least) no dark on the lower mandible. Questions to
check with those that know Crested very well: Does the bill shape really
match Crested much better than Ancient? Do Cresteds often/ever show much
dark on the lower mandible? If so, the bill would be no problem.
3) The tail. It often looks contrastingly dark in AM, like in the HK bird,
while the tail often looks (is?) paler-grey basally in Crested.
4) Head pattern. This is what first really concerned me, is that much of
the vestigial head pattern looks rather closr to Ancient to me than to
Crested.
Based on limited field experience and on discussions with others, Crested
appears to have no very clear non-breeding plumage (just a reduced crest,
perhaps): is this right, Nick, or is there much seasonal variation? Either
way, Crested effectively has a black head with a white "head-band",
broadest on the nape or very least nape-sides. Ancient has clear
non-breeding and breeding-plumages as you know. In
intermediate-plumaged AM (present any time between Feb-March and May),
birds often show some white indent in front of and behind the eye and a
black chin (without the full black bib and head sides of Crested). Worn
birds can also show a fairly strong hint of an eye-ring (like this bird),
something that might be shown by Crested as well (though I have no evidence
of that in either descriptions or images)?
5) Nape, Most significantly to me I guess, ALL AM show a black nape at all
times of the year. ALL Crested, on the other hand, should show either a
white nape (breeding) or at the very least, broad white nape-sides (said by
some to be non-breeding plumage). This bird appears to show an all-black
nape. Why? In specimens Nick, do any of the Cresteds show a black nape
like this bird seems to do?
I can understand why dark parts will bleach and wear paler, but why would
the white nape or nape-sides of Crested seem to wear to solid black as
shown in the shot from the rear while the bird is attempting to fly?
An odd bird, for sure. Considering the relative status of the two species,
I personally would plump for caution, and unless better information comes
to light (eg Cresteds can indeed show a black nape), put it down either as
an Ancient (?) or an indeterminate due to plumage condition. "
Quote from Mr. Nick Lethaby in reply to Mr. Nail Moores's email :
" ..... I have photos of some winter specimens of Jap Murrelet. It's
conceivable that they are first winters and that Japanese doesn't have a
non-breeding plumage. However I was able to find late May specimens of
adults with white appearing in the throat. This to me was strongly
supportive of Jap Murrelets having a adult non-breeding plumage. .... The
bird is so ratty that I agree that it's hard to be sure but I favor
Japanese at this point...."
".. I have attached some specimen pics of alternate, basic (so about this
term but winter isn't really appropriate as I think Jap Murrelets are in
basic from July-Jan), and transitional (from late May). I think this shows
the face pattern is OK but also shows that the white crest/nape area is
still pretty obvious in basic Japanese. ..."
alternate basic
winter
summer
Also, through Mr Simba Chan (Birdlife in Japan), we were able to
contact Mr Koji Ono and he had made a very brief comment. At first
diagnose he belief this bird is NOT a Japanese Murrelet. He will give
supporting reasons later on, so right now we're still waiting for his
decisive answer.
Finally here is a drawing found by Geoff which is quite useful to ID between
Ancient and Japanese Murrelet. It is from a book, 'The Auks' by Gaston &
Jones, OUP, 1998.
1) is Ancient,
2) is Japanese, a is adult summer, b is adult winter.
The text goes further to say ''in winter (Japanese) probably hard to
separate from Ancient Murrelet, except for deeper bill and paler legs".
I would say the Hong Kong bird does show some small white marks just behind the eye, and the second of Nick's basic photos also only shows a small white patch. One of the problems is the poor plumage condition of the Hong Kong bird, very difficult to see what the plumage really is.
Hope that we can expect more information and comments from the OBC E-Group when John & Jemi return.
More Comments and discussion are most welcome, thanks.
PWMK
PS. We must thank Geoff Welch, John & Jemi, Nial Moores, Nick Lethaby, Simba Chan, Uncle Tall and Mr Koji Ono for their generous help.
