Fulvous Whistling-Duck (Fulvous Tree Duck) Dendrocygna bicolor
A few records from southern Europe may possibly relate to genuine vagrants from Africa but the vast majority of records in most of Europe relate to birds that have escaped from captivity.
Note that other species of Whistling-Duck can appear rather similar and in captivity they readily hybridise with one another.
The first set of birds below are wild birds in Africa but the rest are captive birds in the UK.
