Mallard x Northern Shoveler hybrid, Utterslev Mose (Denmark), 17th March 2003 - copyright Lars Vilhelm Hansen
(photo ID: 2596)
This seems to be quite a rarely encountered hybrid, the bird shown in the photos here being a fairly typical individual.
Mallard x Northern Shoveler hybrid (same bird as in photo ID 2596 above), Utterslev Mose (Denmark), 16th March 2003 - copyright Lars Vilhelm Hansen
(photo ID: 2597)
Another similar bird follows. Nice to see a good shot of the upperwing on this one.
Mallard x Northern Shoveler hybrid, southern Bavaria (Germany), December 2015 - copyright Johannes Honold
(photo IDs: 2422-2423)
The following illustration by Joern is based on pictures of a bird from Denmark, a bird from the Netherlands and partly on photos of a bird from USA.
Mallard x Northern Shoveler hybrid - copyright Joern Lehmhus
(illus. ID: 0718)
Joern has written about Mallard x Northern Shoveler hybrids in the German magazine Aves. It's is in German but you can access the PDF of Aves 2 (2011) - the article starts on page 21 with section 6 on this hybrid at page 26.
Mallard Anas platyrhynchos
Northern Shoveler Anas clypeata