Corvid ID help, Con Dao, Vietnam. (1 Viewer)

[John Diener]

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Found this crow in south Vietnam, does not fit with expected species as far as I can tell. My wife and I were thinking it maybe a Juv. Rook, but we don't have a lot experience with these species, would love some help. This bird seems like a juvenile, based on the evenly brown flight feathers. And the bill shape seems to fit with Rook more than any other corvid species we could compare to. (Unless this is a carrion crow with a bum bill? )

Would be a first record of rook for Vietnam if thats the case, I think.

 

[01101001]

Maybe Large-billed Crow. Looks like it's in range.

EDIT: Actually, no records for the archipelago yet in spite of 124 other species being recorded there:

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...or maybe a Rook indeed?

...Slender-billed Crow?
OK, I've run out of ideas.

 

[Grahame Walbridge]

Planned Outage for Some Cornell Lab Services

Several Cornell Lab of Ornithology services will be unavailable beginning March 19 through 6:00 a.m. U.S. Eastern time on March 21. This is a one-time disruption while we migrate more than 1.6 billion eBird observations and additional project data to new servers. After the move, our websites will ha

ebird.org

Found this crow in south Vietnam, does not fit with expected species as far as I can tell. My wife and I were thinking it maybe a Juv. Rook, but we don't have a lot experience with these species, would love some help. This bird seems like a juvenile, based on the evenly brown flight feathers. And the bill shape seems to fit with Rook more than any other corvid species we could compare to. (Unless this is a carrion crow with a bum bill? )

Would be a first record of rook for Vietnam if thats the case, I think.

John, concur your bird is a juvenile (2cy) Rook confirmed by combination of long, pointed bill with nearly straight culmen, head shape and loose feathering to belly. Age is confirmed by presence of retained nasal feathering + unmoulted (worn) remiges. Bill structure readily excludes any of the Large-billed Crow complex, likewise, 'Eastern' Carrion Crow, probably the least likely, is ruled out on bill structure and head shape.

No accepted records from the region (SE Asia) that I am aware with the notable exception of a fairly recent record (year?) from Petchaburi, Thailand was considered of uncertain origin by BCST and consequently not admitted to the Thai List. So, the only issues seems to be provenance.

Grahame

 

[Butty]

Don't juvenile rooks only retain their funny bill for 2-3 months? So this is one that has kept its until mid-January despite having moulted body plumage? Perhaps more likely than that, more likely than it being a first natural record for SE Asia, and more likely than it being a rook kept in captivity in SE Asia, is that it might be a large-billed crow with an aberrant/unusual bill.

 

[Grahame Walbridge]

Don't juvenile rooks only retain their funny bill for 2-3 months? So this is one that has kept its until mid-January despite having moulted body plumage? Perhaps more likely than that, more likely than it being a first natural record for SE Asia, and more likely than it being a rook kept in captivity in SE Asia, is that it might be a large-billed crow with an aberrant/unusual bill.

No, they retain nasal feathering well into 2cy until spring (Apr) while feathers on chin from are lost sometime between Jan-Feb.

Grahame

 

[johnallcock]

I've heard that Rooks have increased in China in the past 10-20 years, which could increase the chance of vagrancy outside the normal range. The first record in Hong Kong was relatively recent (2017) but they have turned up a few times since then. All have been first winter birds, and those that remained all winter have retained the black bill and nasal feathering throughout their stay. Vagrancy into Vietnam (or indeed Thailand) seems possible to me, although I wouldn't have predicted it being as far south as this bird!

 

[John Diener]

John, concur your bird is a juvenile (2cy) Rook confirmed by combination of long, pointed bill with nearly straight culmen, head shape and loose feathering to belly. Age is confirmed by presence of retained nasal feathering + unmoulted (worn) remiges. Bill structure readily excludes any of the Large-billed Crow complex, likewise, 'Eastern' Carrion Crow, probably the least likely, is ruled out on bill structure and head shape.

No accepted records from the region (SE Asia) that I am aware with the notable exception of a fairly recent record (year?) from Petchaburi, Thailand was considered of uncertain origin by BCST and consequently not admitted to the Thai List. So, the only issues seems to be provenance.

Grahame

Thanks Grahame for the reply. A lot of great info in there. We appreciate the feedback.

 

[Larry Sweetland]

Just want to say well done for finding an extralimital black corvid that's not even in the regional field guide! Quite a feat 👍

 

[John Diener]

Just want to say well done for finding an extralimital black corvid that's not even in the regional field guide! Quite a feat 👍

Thanks Larry! We were really excited about it! It nice to finally get some validation.