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Hooded crow or hybrid? (1 Viewer)

SteveTS

Well-known member
A fair few farmland birds come to feed on the beach on a receding tide. Yesterday (18th October 2019) in the mob and accompanying a nice well coloured pair of Stock doves and a few Jackdaws was this Hooded crow.

Hoodies are not often seen here (Lincolnshire), just occasionally in the autumn and winter months. This one had found an intact cockle and was carrying it up 10 to 15 metres or so to drop it repeatedly on the sand trying to break it, the first time that I have seen that.

So Hooded crow or hybrid? And what is the current knowledge of Carrion crow speciation? Links appreciated.

Many thanks.

Regards, Steve
 

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Hybrid - too much black on the mantle, flanks & belly :t:

They're currently treated as separate species, but I've seen some suggestions this might get reversed in the future. Wait'n'see, I guess!
 
I thought ‘Hooded’ was the nominate race.

Laurie -
Hooded Crow is currently Corvus cornix, and has 4 subspecies.
Carrion Crow is currently Corvus corone, and has 2 subspecies (nominate in W Europe, and orientalis in eastern Asia, which may be better treated as a separate species Corvus orientalis)
When Carrion and Hooded are lumped, Corvus corone takes precedence over Corvus cornix, so the latter becomes Corvus corone cornix (both names are from the same date 1758, so this is done on the 'first reviser' principle - you follow whatever the first person to lump them did).
 
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So you are saying that the more restricted range ‘Carrion’ Crow trumps the more widespread ‘Hooded’ Crow as the nominate race? If so i have been labouring over an illusion for over 45 years:-C

Laurie:t:
 
So you are saying that the more restricted range ‘Carrion’ Crow trumps the more widespread ‘Hooded’ Crow as the nominate race? If so i have been labouring over an illusion for over 45 years:-C

Laurie:t:
It doesn't depend on range, it depends on history of naming. Most important, whatever name was published first, wins. If two names are published at the same time (which Corvus corone and Corvus cornix are; both in Linnaeus's 1758 Systema Naturae page 105), then the one that has priority depends on the choice of whoever first lumped them. Quite often, 'page priority' was used in this choice: it can be argued that since Corvus corone is higher on the page than Corvus cornix, it was therefore written ten minutes earlier, so is the older name. This is bit artificial, so page priority is no longer used now, but it often was in the past, and the choice of the first to lump still stands.
 
As a further aside - through historical accident, species are often first described from isolated populations at the edges of their ranges. Red-tailed Hawk Buteo jamaicensis is a good example; not difficult to guess, it was first described from Jamaica, and nominate Buteo jamaicensis jamaicensis is restricted to that island and a couple of others nearby. The widespread North American populations are subspecies Buteo jamaicensis borealis (eastern N America) and Buteo jamaicensis calurus (western NA), with several other subspecies elsewhere on the fringes of the range. Only history of naming matters, not which has the largest or most central part of the distribution!
 
I am aware of a lot of what you have said but is it just a technical point on order of naming or is Hooded the accepted nominate race but because of protocol has been relegated by Carrion Crow just on a first-come first-named basis? I have always understood Hooded to be the nominate with others the ssp despite the ‘naming’ procedure?

Laurie:t:
 
Carrion has always been the nominate subspecies when the two are lumped - I'm not aware Hooded has ever been considered the nominate subspecies by anyone in that situation.

Linnaeus of course lived within the range of Hooded, so he might have been expected to have it as his 'first crow' - but since he treated the two as separate species, that situation didn't arise. Unfortunately, I've no idea who the first person to lump them was; you'd need to get into their mind to find their reasons for chosing Carrion to be the one with precedence.
 
Carrion has always been the nominate subspecies when the two are lumped - I'm not aware Hooded has ever been considered the nominate subspecies by anyone in that situation.

Linnaeus of course lived within the range of Hooded, so he might have been expected to have it as his 'first crow' - but since he treated the two as separate species, that situation didn't arise. Unfortunately, I've no idea who the first person to lump them was; you'd need to get into their mind to find their reasons for chosing Carrion to be the one with precedence.

Simple, C. corone and C. cornix was both described in 1758 ; in case they were described in different publication, that's the one described first that takes the name of the lumped species. In case they were both described in the same publication, that's the one appearing first in the publication (for example, if on the same page, the one of the line above the other...)

The rule is strict and no one can "chose" the name.
 
Simple, C. corone and C. cornix was both described in 1758 ; in case they were described in different publication, that's the one described first that takes the name of the lumped species. In case they were both described in the same publication, that's the one appearing first in the publication (for example, if on the same page, the one of the line above the other...)

The rule is strict and no one can "chose" the name.

Except, as Nutty explained in post #6, page priority does not apply; you need a first reviser action to select which name has priority.
 
Except, as Nutty explained in post #6, page priority does not apply; you need a first reviser action to select which name has priority.

I didn't see that post indeed, but he said the same...

This is bit artificial, so page priority is no longer used now, but it often was in the past, and the choice of the first to lump still stands.

I didn't know that page priority was no longer in use though.

By the way, Hooded Crow is certainly a sub-species of Carrion Crow for that. I state HBW Alive.

Hybridization apparently inhibited by sexual and social imprinting, but genetic differences slight and gene flow strong, with German corone closer to cornix than to Spanish corone
 
Carrion and Hooded should be treated as one species. A genomic study shown that the only difference is a small region of genome responsible for coloration. (https://science.sciencemag.org/content/344/6190/1410). This is one example where scientific evidence for splitting is favored and evidence for lumping is ignored.

By the way, this bird shows a something typical for Hooded x Carrion hybrids: the black color moves from the end of the torso towards the front. More extreme hybrids have little grey only on neck and breast around the lower edge of the black hood. More Hooded-like hybrids have black undertail coverts and part of the belly (which are grey in pure Hooded Crow).
 
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Carrion and Hooded should be treated as one species. A genomic study shown that the only difference is a small region of genome responsible for coloration. (https://science.sciencemag.org/content/344/6190/1410). This is one example where scientific evidence for splitting is favored and evidence for lumping is ignored.

Not ignored by all, as HBW / Birdlife lump them ; I publish page on bird species (in French for now) an you can see than my page on Carrion Crow was published in December 2018 including Hooded Crow as a sub-species.
 
Hybridization apparently inhibited by sexual and social imprinting, but genetic differences slight and gene flow strong, with German corone closer to cornix than to Spanish corone


Interesting! But makes we wonder why they remain geographically so contained in their own regions, and why hybrids are found in such narrow confines. You would think that even if they didn't interbreed, they would mix into each others' territories.
 
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