South African Hornbill species kept outside Africa?

[Jaguar_X]

I have recently wondered how common South African indigenous hornbill species are in the rest of the world. I have done this with Turaco before, but now it is time for hornbills.

In South Africa we have 6 species of Hornbill, namely:
•Southern Yellow-billed Hornbill
•Southern Red-billed Hornbill
•African Grey Hornbill
•Crowned Hornbill
•Trumpeter Hornbill
•Southern Ground Hornbill

The last 2 species I am pretty sure are common in zoos all around the world, but as for the first 4, I have no clue. My best guess is that they are either rare or non-existent outside (South) Africa.

Southern Yellow-billed Hornbill are kept at 3 zoos that I know of in South Africa, though I have never seen or heard of them being kept in our private trade.

Southern Red-billed Hornbill are also not kept in our private trade to my knowledge and are only kept at 2 zoos, even though Birds of Eden lists theirs as Northern Red-billed Hornbill, I am pretty sure that is only because they were recently split and the park only used the scientific name they previously had, which is now the one of the Northern Species, instead of updating it to be the Southern species.

African Grey Hornbill are the most common of the 4 species that I am unsure about, with a total of 4 zoos holding them that I know of. They are also not in our private trade to my knowledge.

Lastly we have the Crowned Hornbill. The only place I could find in South Africa that holds these are Umgeni River Bird Park.

How common are are these species outside of South African zoos or are they even kept?

 

[Dhole dude]

All of the species mentioned above are held in North America, to varying degrees of regularity.

 

[Hvedekorn]

In Europe, trumpeter hornbills and southern ground hornbills are indeed common. Crowned hornbills and grey hornbills are not anywhere near as common, but still held in a few places. I've seen grey hornbills a couple of times, but I have actually yet to see crowned hornbills. Southern yellow-billed hornbills and southern red-billed hornbills are absent from public collections (I have no clue about private hands) - we have eastern yellow-billed and northern red-billed ones instead.

 

[Great Argus]

In terms of public collections in North America (may be higher, but a good rough idea)

Southern Ground Hornbill - approximately 40 collections, also a few privately I believe.

Crowned Hornbill - 2 collections, unsure if in private trade.

African Gray Hornbill - 1 collection, might be a few privately.

Southern Yellow-billed Hornbill - 3 holders, think there's a few privately too.

Red-billed Hornbill - I don't think ours are the Southern type, but I don't know for certain.

Trumpeter Hornbill - approximately 18 collections, also very common privately.