14 de septiembre de 2021

arctic warbler complex | Kamchatka Leaf Warbler\Arctic Warbler/Japanese Leaf Warbler

This matter is well above my paygrade but it makes for interesting reading.
It is probably not the latest on the subject but sofar it appears to have been widely accepted.

On the species separation of 3 Arctic Warbler type Phylloscopus Leaf Warblers.
Arctic Warbler | Phylloscopus borealis | コムシクイ
Kamchatka Leaf Warbler | Phylloscopus examinandus | オオムシクイ
Japanese Leaf Warbler | Phylloscopus xanthodryas | メボソムシクイ

It argues that Arctic Warbler, Kamchatka Leaf Warbler and Japanese Leaf Warbler are three branches of the same tree and very hard to distinguish in the field - under normal circumstances even impossible.
Call and song of these birds are good for a proper ID to species level. In the breeding areas in the breeding season a field record may be identifiable. During migration it is considered impossible.

https://www.researchgate.net/publication/227729552_The_Arctic_Warbler_Phylloscopus_borealis-_three_anciently_separated_cryptic_species_revealed
(pdf is downloadable from within this page itself)

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12 de junio de 2021

Large-billed Crow or Carrion Crow

seeing 10s of new Japanese crow photos a week at inat makes me understand that I know less than I think I do.
I thought i had it sort of figured out with this pair but...sometimes it is hard.
Sure the obvious birds are just that obvious...other than that..

In the field ID is often straightforward. Birds call differently, behaviour can be viewed. This post deals solely with ID from photos, which more often than not seems to be surprisingly hard.

Comparison sites I could find are focused mainly on the obvious differences.
I hope to collect some info here

Carrion Crow Large-billed Crow
ハシボソガラス ハシブトガラス

questions I ask myself:
The curve in the upper mandible could be something to work with
Is the feathering of the saddle an indication?
Tail-width and length seem to be greater with LbC but is it a fact?
What other features could help?

big bill? large tail? This appears to be a Carrion Crow anyway
https://www.inaturalist.org/observations/82613508
(the saddle may be a feature)

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26 de diciembre de 2020

large white-headed gulls in Japan/Korea/Taiwan

some collected links on large gulls in East-Asia (for my benefit...maybe for yours as well)

extensive (to understate it) website full of good stuff: http://www.gull-research.org/
some featured chapters are a bit hidden
like a Vega chapter
http://www.gull-research.org/vega/1cysept.html

all species, full size photos
http://mituyubi.com/menu/menu.html

article on separation of three herring gull-type gulls
https://www.shanghaibirding.com/gulls-moores/

http://strix.main.jp/?page_id=48&tagname=xheuglins_gull_taimyrensis&paged=8
a huge stream of gulls (and other jp birds) in all sorts of poses

a blog (discontinued)
http://larusology.blogspot.com/

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30 de noviembre de 2020

the other grey-eyed Japanese blue Zizina emelina | 0 records in Inat

Where are records of Zizina emelina?
They should be fairly common in Japan too
https://blog.goo.ne.jp/matsuhiroblog/e/fe5e98e114268d5dd507d9f1254f2016

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15 de octubre de 2020

Japanese hard to ID fritillaries

Warning
this might be an oversimplification
3 types of virtually (or completely) indistinguishable species in the field, but genetically different. These species maybe divided into a few subspecies. The genus is unclear, so is the exact link to mainland Asian species.

SATO
1 occurs on lower altitudes and lowlands: サトウラギン Fabriciana adippe pallescens

YAMA
2 occurs in higher altitudes: ヤマウラギン Fabriciana niobe

HIME
3 occurs Hokkaido and around Nikko (what is the exact area?)
(info via g.transl from: https://yoda1.exblog.jp/13831207/) ヒメウラギン Fabriciana vorax locuplex

according to https://yoda1.exblog.jp/13831207/
it seems that YAMA has less of a curve in the forewing edge (compared to SATO)

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11 de septiembre de 2020

White egrets and herons | East Asia

Struggling with distant white egrets, this might give an answer
https://ebird.org/malaysia/news/chinese-egrets-in-malaysia-where-when-and-how-to-find-them

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02 de julio de 2020

jp dragonfly pages

useful odonata pages
https://www.odonata.jp/03imago/index.html
http://yagopedia.com/refbook.php?tombo=33 (maybe around for years, first time I see it was july 2 2020)

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23 de junio de 2020

Neope goschkevitschii vs Neope niphonica

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25 de abril de 2020

ID of Mnais demoiselles in Japan - work in progress

My first odonata in Japan were those gorgeous orange-winged streamdwellers I had hoped to see. Then came the difficulty of ID'ing them properly.

Hopefully i will be able to store here some information on the two Mnais-species represented in Japan..

WORK IN PROGRESS --- INITIAL PHASE

1 id certain based on confusing map:
https://www.inaturalist.org/observations/18800588
wingcolour of female is smokey: costalis only feature

1 id certain based on low number of cells next to pterostigma
https://www.inaturalist.org/observations/18806161

https://www.inaturalist.org/observations/18869536

costalis: as no orange winged pruinosa lives in this area
https://www.inaturalist.org/observations/22020143

read more about wingcells and veinage
http://www.odonata.jp/03imago/Calopterygidae/index.html#vein
https://link.springer.com/chapter/10.1007/978-981-10-4956-9_17

edit 26 april 2021: Note this record of otherwise a quite standard looking costalis (in North-Japan, where pruinosa does not occur) with what seems a small amount of cells adjacent to pterostigma ... not sure what to make of it...
https://www.inaturalist.org/observations/64427110

wings of both male and female of both species
https://ai2-s2-public.s3.amazonaws.com/figures/2017-08-08/e307ef137cc53f28a193ecb5c2d5a25f10c122b6/2-Figure1-1.png

further info
on habitat segregation of pruinosa and costalis
https://www.tandfonline.com/doi/abs/10.1080/13887890.2012.762745

and in Japanese
https://yoda1.exblog.jp/19813772/
on cellnumbers (different approach, hopefully same result)
http://dranathis.blog.fc2.com/blog-entry-352.html

CELL COUNT important feature? (maybe a simplification on my part)
cell count may be a good feature (as odonata.jp explains) Sofar (4 june 2020) I only found one costalis male (ID based on location up north) with something that looks like bigger cells next to the pterostigma
https://www.inaturalist.org/observations/17243744

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20 de noviembre de 2019

large Japanese cormorants*

Japanese Cormorant | Great Cormorant
ウミウ | カワウ

The two bigger Great Cormorant (Phalacrocorax carbo) and Japanese - or Temminck's - Cormorant cause quite a bit of ID-trouble.
Subtle differences are recognized but not always easily applied in the field.
Because I too struggle often, I will give the main ID-paper links here... in the hope to get this problem fixed sometime soon and to help others maybe to ID their Japanese larger Phalacrocorax records.

difference JC en GC
(Gular Pouch is the yellow bare skin just behind the bill, touching the eye)

Great Cormorant
Gular Pouch angle = 85°* and straight sides (more or less) CONVEX

Japanese Cormorant
Gular Pouch angle = <85°, sharp angle and curved sides (more or less) CONCAVE

gular pouch angle in Western Europe
On the gular pouch difference between ssp carbo and ssp sinensis
http://web.tiscali.it/cormorants/pdf/Stuart_ardea2004.pdf
Gular pouch wise I would think Japanese cormorants in general are closer to c.carbo?

the 85-degree angle has been determined for sinensis, the sister ssp from the continent, which up to now is considered not distinguishable from hanedae in the field.

Temminck's <> Great Cormorant
http://www.birdskoreablog.org/?p=14250
https://www.dutchbirding.nl/journal/pdf/DB_1999_21_1.pdf
http://www.biodic.go.jp/kawau/d_hogokanri/hunt_leaflet.pdf

general features to be checked:
Phalacrocorax capillatus
PRO
broad and high ending white cheek (not a very reliable feature)
angular yellow patch
slightly more gentle , sloping head.

Location: both species may occur inland and in coastal areas. I don't think that is a safe IDentifier. General opinion though apparently is that capillatus is more tied to the coast.
edit 2021: i have come across very few (if any) shots of temminckś inland. But that could be the bias playing up. Confirmed Temminck are mostly at sea or on/near the seaboard.

the hue of adult breeding bird mantles is often suggested to be a distinguishing feature. As the perception of colour greatly depends on the lighting I suppose it is a feature that should probably be used as a supporting feature rather than a prime identifier (but that is just a layman speaking, perhaps)

*
NB. I don't claim scientific status for these scribbles. It's just a reminder of what to look for.

NB. feel free to comment, add links to (Japanese) texts or....

On the gular pouch difference between ssp carbo and ssp sinensis
http://web.tiscali.it/cormorants/pdf/Stuart_ardea2004.pdf
Gular pouch wise I would think Japanese cormorants in general are closer to c.carbo?

thanks in advance.
Gerben

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