Unknown Duck (Mareca hybrid?)

Looks fine for a Chiloe Wigeon to me. Was this in Simmons Aviary?

@birdsandbats Yes, I was just thrown off by the side feathers

Both the head and size feathers look off for a Chiloe wigeon, but what it is I can't say....

Yeah looking back I'd think a hybrid. What other duck species are in the aviary?

@birdsandbats A huge variety unfortunately. Here are the ones that might make sense:
Blue winged teal, marbled teal, northern pintail, baikal teal, gadwall, and possibly mallard,

Mallard seems a good possibility to me - there's a yellowish wash on the bill base, strong green throughout the back of the head as well as a greenish wash to the top of the head, and orange feet. No real good way to say for sure though.

It definitely is a hybrid and Chiloe wigeon parentage looks likely, the tertials and the bill color indicate wigeoin hybrid, the head pattern indicates chiloe wigeon hybrid ...
bill shape indicates that the second parent is something mallard-like, but maybe a species that does not have a full breeding plumage. Laysan duck or Hawaiian duck could be a possibility for that second parent if kept at the zoo

For comparison, these are Mallard x Chiloe wigeon
https://pbs.twimg.com/media/D3zMC6rWsAE8blI.jpg
Hybride Wilde Eend x Chileense Smient - Anas platyrhynchos x Mareca sibilatrix
Hybride Wilde Eend x Chileense Smient - Anas platyrhynchos x Mareca sibilatrix
They seem more yellowbilled in most cases, and often less longbilled, than the bird in question
So i could well live with the idea of Laysan duck or Hawaiian duck x Chiloe wigeon for the bird in question