Tufted ducks and friends

Recently I have seen tufted ducks on a little river near here. (Not on the river I usually visit.)


Whenever I have seen these ducks, they are always hanging out with some ducks that are not tufted ducks. I think they are pochards. All of these ducks are diving ducks, and they look like children's toys. They look, somehow, painted.





But there are some mysteries about these ducks. Well, at least to me they are mysteries. Maybe you can help me to understand what is going on.

The first mystery is this: Where are the female tufted ducks? In the Wikipedia pictures, the female is brown. I have never seen a brown duck at the river. There seem to be only males.

The second mystery is why these two types of ducks are always hanging around together. I thought at first they were male and female, but although they are both diving ducks (I know because I have seen them both dive), I cannot find any pictures that show a male and female that look like these ones do.

I did, however, find some pictures that made me wonder whether the pochards are actually hybrid pochard/tufted ducks. But that still leaves the question of why they are all male. Unless, of course, some of them are actually female and I just haven't found the right pictures yet and matched them up.

Also, I wonder why this particular tufted duck (below) has some brownish feathers under its wings? The others are just black and white. Is it also some kind of hybrid?

And finally, did you know before seeing this picture that ducks had tongues? I didn't. Actually, I hadn't ever thought about it, and I suppose if I had I would have guessed that they did. But even so, I find this tongue rather surprising.