Wood Duck also (North) American Wood Duck and Carolina Wood Duck Aix sponsa

Petrol cheeks
Wood Duck male
The drake Wood Duck (above) in full breeding plumage is one of the most beautiful ducks, second only to the Mandarin.
Wood Duck male
Wood Duck
Wood Duck drake
The Wood Duck, also called Carolina Wood Duck, is native to the USA. Birds in the southern US are resident all year but northern birds migrate south for winter.
They are rare vagrants to western Europe where there are also some feral escapees from ornamental collections.
Wood Duck male
Wood Duck male
Wood Duck
Like the related Mandarin Duck, the Wood Duck has colourful geometric patterns, a maroon spotted breast and gold vermiculated sides.
Wood Duck
Wood Duck
Wood Duck male
Wood Duck female
Wood Duck female
Wood Duck female
Although beautifully marked and crested, the duck (female) is, as usual with many ducks, much plainer to give camouflage when nesting. She sometimes has a slight green tinge to the crown (visible in centre picture above).
She is similar to the female Mandarin duck but with a thicker white eye border in a horizontal teardrop shape without the bold line backwards that the Mandarin has. She also has a fine yellow direct border to the eye.
Wood Duck
Wood Duck
Wood Duck
Wood Duck pairs
Wood Duck eclipse
Wood Duck eclipse
Wood duck
Like many drakes, the Wood Duck's wardrobe is seasonal and the striking breeding plumage of April shown top and right is replaced by one similar to the female by end summer (first two photos above in July UK show transformation nearly complete). Remaining colour on bill and white neck will fade but red eyes will remain a giveaway even though the close eye border has turned from red to the yellow of the female.
The photos above (distant, poor quality) appear to show an eclipse Wood Duck drake with a Mandarin female.

The white border to the eye of the female extends back like spectacles as is usual for Mandarins, but there is an unusual second parallel line extending back halfway. Also the round part of the white border seems thicker, as in Wood Duck.
Some Mandarins do have a parallel shadow white line.
-- This one was with other Mandarins -- but both of these also seem to have a splash of yellow on their bill?