Yes, I did learn about that in biology when I wasn't too busy sleeping or smoking cigarettes.I know certain fish turn the opposite sex when there is a lack of that sex in their environment (the most dominant clownfish becomes female [All are born male] and grouper females can turn male if there are none available to breed with), but I find it very hard to believe that birds are the same way. This sounds like it's just secondary traits changing because of hormones, not literally becoming a fertile specimen of the opposite sex

That's why I'm open to the slight possibility it could happen in a very rare case scenario. Even that article pointed out that the duck died shortly after this supposed transformation occured though. So if and when it happens the bird maybe doesn't live long enough to have a good case study done.

I maintain that I can't believe it until I see it happen for myself.
A lot of the posts I see here on byc about it are nothing more than simply a drake changing from nuptial to eclipse plumage.