Walking beside the Water of Leith – and last week on the canal, too – I have often seen large ducks with a somewhat vicious look hooked beak. I know these ducks are either goosander or merganser, but I can never remember which.
Instead I just call them “funny ducks”.

After taking this picture last Thursday, I once more had to look them up in my bird book to see if they were goosander or merganser.
I realised why I find it so hard to remember. They are goosander; the latin binomial for which is
Mergus merganser.
So goosander are
M. merganser.
Just to make sure we’ve got this straight, merganser are
M. serator.