unidentified Aythya hybrid Aythya sp. x Aythya sp.

I've been through several iterations in trying to resolve the identity of this hybrid, assuming that the parents were most likely species in the collection. Several of these were contenders for a parent, including the two birds it was next to when I first saw it: Ferruginous Duck could have led to the warm reddish tones and the clear-cut white belly and Scaup could have given it the broad body shape and white face.

There was a Rosybill Netta peposaca with it too, and it seemed quite a bulky bird - for a while I wondered if this could this be a parent? No combination of these species seemed to quite satisfy though. No combination would be expected to show such a prominent pale band on the bill for a start. Then I started to wonder whether one parent could be a species I've never seen in this collection: Hardhead Aythya australis. Indeed the bird looks quite close in appearance to a Hardhead, though it isn't quite right for a pure bird. In my latest photos I think I can just make out a hint of a slightly raised area at the base of the bill which might lend support to my idea of it being a Rosybill hybrid, but it's not prominent enough to be convincing.

For a while I favoured Hardhead x Rosybill as the solution, but I find myself moving away from that idea again - the jizz is all Aythya, albeit a bulky one. So I'm back to Ferruginous Duck x Scaup as we thought early on - but is that right?

click for larger image click for larger image
click for larger image click for larger image
click for larger image click for larger image
click for larger image click for larger image

unidentified hybrid, Blakeney Collection (Norfolk, UK), 1st December 2012

 

click for larger image click for larger image
click for larger image click for larger image

unidentified hybrid, Blakeney Collection (Norfolk, UK), 4th December 2010

 

click for larger image click for larger image
click for larger image click for larger image

unidentified hybrid, Blakeney Collection (Norfolk, UK), 12th February 2011

 

click for larger image click for larger image
click for larger image click for larger image
click for larger image click for larger image

unidentified hybrid, Blakeney Collection (Norfolk, UK), 12th March 2011

 

click for larger image  

unidentified hybrid, Blakeney Collection (Norfolk, UK), 24th November 2013