Hello,
yes, I agree with Butty, final conclusion will certainly be a Northern Shoveler, but its a remarkable bird for me too:
yes, ""strange" Shovelers will easy be overlooked because they are regular easy to identify by monster bill and distinct feeding beaviour (regular feeding in groups, all foraging in the same direction with breast lowered in the water and heck slightly held up - this enhanced by cubic square body and heavy front end).
But your bird seems to have a mixture of "weird"= not fitting together different age features:
- an all blackish bill of a male Shovler, lacking any orange (yish) female-type hues or any paler area of some juvenile birds. Its rare for a juvenile to have an all black bill in september???
- a bright orange iris, lacking yellowish tinge or brownish/colder/dirty hues
Yes, the word intersex Shovler in eclipse plumage came into my mind. I hope for Jörn and others to jump in.