Common Magpie subspecies (1 Viewer)

[01101001]

OK, I've been a little bit torn between posting it here, in Bird Identification Q&A and in Bird Taxonomy and Nomenclature.

While browsing through photos of Common Magpies in the Macaulay Library, I noticed an interesting feature: the white cross stripe above the rump varies in thickness between western and eastern birds. Namely, eastern birds show a thick white stripe, while western birds show a thin white stripe. There is some variation within these two groups, but it seems rather slight compared to the abrupt step in plumage characteristics, which takes place in western Germany and--now more tentatively due to limited data--runs along western Switzerland and the Italian Apennines. At the contact zone there are also birds with intermediate characteristics (a broad off-white stripe). Some areas with conflicting/inadequate data include Ireland, Scotland, far south-eastern Norway and southern Sweden. Here--in central Poland--all magpies appear to consistently sport a broad white stripe. If confirmed by evidence other than anecdotal, this pattern of distribution doesn't correspond with what is known about Common Magpie subspecies. Thoughts?

The map I used: https://www.researchgate.net/figure...-pica-and-collecting-locations_fig1_317579723

Broad white stripe:
northern India, ssp. bactriana (ML441474901 Eurasian Magpie Macaulay Library),
western Russia, ssp. fennorum (ML204751761 Eurasian Magpie Macaulay Library),
central Greece, ssp. pica (ML357270851 Eurasian Magpie Macaulay Library),
western Germany, ssp. pica (ML216960221 Eurasian Magpie Macaulay Library)

Thin white stripe:
northern Portugal, ssp. melanotos (ML337196481 Eurasian Magpie Macaulay Library),
Cornwall, England, ssp. pica (ML443017491 Eurasian Magpie Macaulay Library),
northern France, ssp. pica (ML509608451 Eurasian Magpie Macaulay Library)

Both forms:
western Germany, ssp. pica (ML483883641 Eurasian Magpie Macaulay Library),
Apennines in western Italy, ssp. pica (ML286596691 Eurasian Magpie Macaulay Library)

EDIT: These photos are solely for illustrative purposes; for the record, I went through many more of them.

 

[01101001]

Maybe someone has access to a corvid reference that covers the ID criteria for the various subspecies--e.g. Wikipedia's page describing jackdaw subspecies utilises Derek Goodwin's 'Crows of the world' (old but reportedly still good)? This way I would know whether or not and to what extent is the upper rump/lower back white band used in magpie identification down to ssp. level?

Besides, has anyone paid closer attention to magpies flying around and could either confirm or debunk the inferred distribution pattern (or provide more information wrt Ireland, Scotland/Northern England up from Yorkshire, the Oslo area or lowland Sweden)?

What I am trying to say is that, although the width of the white band may be a clinal feature in western (from a thin white band to a (nearly?) nonexistent white band--it may only appear nonexistent due to the photo quality) and eastern birds (from a thick white band to an even thicker white band with a slightly concave upper and lower border), the most pronounced difference is observed where it definitely shouldn't--that is running down the middle of the nominate subspecies range (a bit similar to the boundary seperating Carrion Crow and Hooded Crow, and hence my interest in Scotland and Ireland, which look inconclusive, and there are not enough photos in the eBird database from these two regions). In other words, Common Magpies from western Germany are more similar to magpies from India than to magpies from eastern France, and Common Magpies from eastern France are more similar to magpies from Portugal than to those from western Germany, and there seems to be no accounting for this difference, not that I know of. I'm surely biased, but I think the difference in width is a major (field) character.

 

[Jacana]

An extract here from the BirdsoftheWorld website if it's helpful for you:

Races differ mainly in intensity of gloss in black areas of plumage, extent of white in wing, prominence or absence of white in rump, comparative tail length and size: fennorum is larger and has more extensive white on rump than nominate; bactriana has prominent white rump, more extensive white in primaries (showing as white tips on closed wing).

They also illustrate pica, leucoptera, melanotos and camtschatica. Eurasian Magpie - Pica pica - Birds of the World

As far as I know, no one has done a thorough sampling of magpie populations across their range to look at population structure. As with the majority of European species with large ranges, there are bound to be interesting colonisation pathways and signatures of past climatic events, driving populations into refugia during glacial maxima.

If you're interested in pursuing this further, I would recommend seeing if you can access museums to look at specimens, which will give you a better idea of the patterns of this characteristic than photos can provide.

 

[Xenospiza]

The magpies from SW Europe (up to the southern Netherlands) were once treated as subspecies galliae.
Kleinschmidt even looked at the rump band to separate this form!
There was some comment about his description; here he is defending himself (in German): https://www.zobodat.at/pdf/Falco_19_Sonderheft_1923_0028-0030.pdf

 

[01101001]

An extract here from the BirdsoftheWorld website if it's helpful for you:



They also illustrate pica, leucoptera, melanotos and camtschatica. Eurasian Magpie - Pica pica - Birds of the World

As far as I know, no one has done a thorough sampling of magpie populations across their range to look at population structure. As with the majority of European species with large ranges, there are bound to be interesting colonisation pathways and signatures of past climatic events, driving populations into refugia during glacial maxima.

If you're interested in pursuing this further, I would recommend seeing if you can access museums to look at specimens, which will give you a better idea of the patterns of this characteristic than photos can provide.

That all together would explain a lot, so thank you very much (unfortunately, I can't access the pictures, as I don't have an account at Birds of the World).

The magpies from SW Europe (up to the southern Netherlands) were once treated as subspecies galliae.
Kleinschmidt even looked at the rump band to separate this form!
There was some comment about his description; here he is defending himself (in German): https://www.zobodat.at/pdf/Falco_19_Sonderheft_1923_0028-0030.pdf

Thanks a lot, German will do--I have some school background plus many online dictionaries to consult.

 

[Andy Adcock]

An extract here from the BirdsoftheWorld website if it's helpful for you:



They also illustrate pica, leucoptera, melanotos and camtschatica. Eurasian Magpie - Pica pica - Birds of the World

As far as I know, no one has done a thorough sampling of magpie populations across their range to look at population structure. As with the majority of European species with large ranges, there are bound to be interesting colonisation pathways and signatures of past climatic events, driving populations into refugia during glacial maxima.

If you're interested in pursuing this further, I would recommend seeing if you can access museums to look at specimens, which will give you a better idea of the patterns of this characteristic than photos can provide.

What race are the birds on Cyprus?

 

[Jacana]

What race are the birds on Cyprus?

Nominate, on current understanding.

 

[Andy Adcock]

That's what I thought Will, thanks.

 

[01101001]

What I meant by 'intermediate' (I didn't include any such photo above):

Escaped

Back in August, a cousin and her husband visited Scotland and we arranged to meet up at Loch Leven RSPB reserve, as it was about half-way between us. It was good to catch up with them after many years. This reserve used to be called Vane Farm...

www.birdforum.net

Sidenote: From a philosophical standpoint--even before it's come up in this thread--I've been recently wondering why taxonomy can't seem to transition from the mediaeval killing of birds (aka harvesting skins)--given the recent advances in 3D imagery, scanning and holography--to achieve a more ethical, sustainable, easily accessible and durable result.