Mariana mallard at SeaWorld San Diego

[vogelcommando]

Came across some intresting articles about the Mariana mallard ( Anas oustaleti ).
This species is not recognized by all scientist ( believing it being a hybrid form ) and now ( almost ) surtain extinct.
The last known 3 specimens ( 2 males and 1 female ) were catched in 1979 and one of the males was released again - being the last ( known ) wild specimen of its species and was never seen again....
The pair was first brought to Hawaii and then send to SeaWorld San Diego with the intention to start a breeding-programm ( with one pair.......!? ).
This failed however and the last bird - the last of its species ! - died 1981 at SeaWorld.....
I have several questions about this species and it's holding at San Diego and because all this happened quite recently I hope some ZooChatters can help.
First of all, have any ZooChatter seen ( or even photographed !? ) the last pair during their time at SeaWorld San Diego and if so would it be possible to tell about it ?
Are there any published notes, articles or other information about the pair during their time at SeaWorld San Diego ( like enclosure discription, did they lay eggs and so on ) ?
Is it known when the birds exactly died in 1981 ? If so, it would be one of the few species where the exact date of extinction is known.
Hope somebody can help !

 

[FBBird]

Mariana Mallard....

I thought it was pretty generally accepted that this was a hybrid population of Mallard x Pacific Black Duck.

 

[vogelcommando]

There are quite a lot of scientists which think so but also quite a large group which still is sure it was a species on its own. I'm with the second group and seen the efforts made in 1979 -at least at that time - many more were putting time and money in it to save it.
Do you know if there is done any genetic ( DNA ) research to proof the hybrid or own species theory ?

 

[Chlidonias]

I don't think there have been any DNA studies done on oustaleti - I've never heard of any at any rate and I couldn't find anything just now with the aid of Google.

The general consensus is of the bird being of hybrid origin, but there are still those who believe it is a true species or a valid subspecies of mallard (for some reason I couldn't see anywhere that treated it as a subspecies of Pacific black duck which would make more sense). Pretty much all the hybrid side refer back solely to the 1948 paper by Yoshimaro Yamashina in Pacific Science. He studied most of the available specimens (most of them were in Japanese museums) and decided they were hybrids due to their appearance. If I am reading his paper correctly, his argument is that there was a native population of Pacific black ducks Anas superciliosa (at that time generally treated as a subspecies of the spot-billed duck Anas poecilorhyncha) but vagrant mallards Anas platyrhynchos reached the islands and interbred with the local birds. He describes how the majority of specimens most closely resemble superciliosa and relatively few platyrhynchos.

My own opinion after reading the paper is that it certainly shouldn't be treated as a full species, but rather as a superciliosa population or subspecies which has had platyrhynchos genes bred into it. (That is, not a fully hybrid population but more of a mixed hybrid and pure population; sort of the way that in New Zealand we have lots of hybrid superciliosa x platyrhynchos which dominate the population but there are still pure superciliosa as well).