Hybrid duck (?) in cathedral aviary at Pairi Daiza, 2023-10-13

Not sure if it's just due to the damaged/out of place wing feathers, but that large blue speculum reminds me of Hartlaub's duck- possibly barking up the wrong tree but would Hartlaub's hybridise with a shelduck species?

Maybe Common pochard x Common eider? No idea though.

The aviary has Common eider, Common pochard and Ruddy shelduck (at least, according to the most recent species list I have) and I honestly see a bit of all birds in here so I really have no idea. Maybe the ducks got freaky in the sheets and had a three-way hybrid?

I can personally only see the Ruddy shelduck and eider parentage. I didn't even realise they could hybridise.

It is extremely likely that this is a hybrid Common Eider x Ruddy shelduck, but I´d like to see more photos.

Hybrids Common Eider x Common Shelduck are rare, but well known even in the wild, and years ago, I have myself seen a male Common Eider displaying to Ruddy shelducks at Saupark Springe, Germany

another photo of the same bird by GalenMarek

https://www.zoochat.com/community/attachments/upload_2023-12-20_11-24-6-png.673394/

I also photographed this individual with a ruddy shelduck.

Ruddy shelduck (Tadorna ferruginea) and European eider X Ruddy shelduck hybrid ( Somateria mollissima mollissima X T. ferruginea), 2023-10-13 - ZooChat

yes, definitely an odd cross of Eider and Ruddy shelduck.

in body shape it has some resemblance to Eider x Shelduck which has occurred in the wild in Germany, the Netherlands and the UK