The tale of the not so funny Scaup

I found this bird at the beginning of March on a reclamation pond close to the mouth of the Yahata Riverin Itsukaichi City, Hiroshima.

I wasn't sure of it's ID, as it seemed to me from the poor views and shots that I got just before dusk to show characteristics of Lesser and Greater Scaup. It semed to have a small black nail, subtle grey vermicualtions on the flanks and quite tightly packer darker grey vermicualtions on the back all pro- Lesser. However, it did seem too round-headed and long necked for Lesser, and the bill shape/pattern at times resembled both species depending on which way the bird was facing. It seemed to spend all its time on the freshwater pool, rather than on the nearby estuary with the flock of 250+ Greater Scaup. It also seemed to swim always with it's rear end raised..however I wasn't sure which species it was..or if it might even be a hybrid. Unfortunately, the first time round I could not get any shots of the wings. The pond is on a private site and access is only really possible on Sundays, so I had to wait two more weeks until th local bird club meeting at the site to have another look.

After about 5 minutes I relocated the bird, among the other ducks,,and this time after spending 30-40 minutes I finally managed to get some shots of the wings, which prove it is not Lesser and most likely a young male Greater..though the slightness of the black nib on the end of the bill still bugs me.