Some things I definitely didn't know about birds

[Jubal]

Article link:
How does a duck change its sex?

Basically, female birds with ovarian problems can literally naturally change sex, because they stop producing oestrogen, and this can actually lead to a bird with full male secondary characteristics and the capacity to father offspring. I hadn't even really realised just how different the sex hormones are in other vertebrate species, I'd assumed that X/Y was actually common among vertebrates, and I certainly didn't know that the primary inhibitor hormone is oestrogen in birds whereas it's testosterone in humans. It's rare that an avian natural FtM sex change happens succesfully, primarily because the change is started by some sort of major ovarian problem, but it's fascinating that they can do it at all in the first place.

[Clockwork]

Weird. +1, nice info.

[Pentagathus]

Hot.

[Jubal]

Also Mandarin ducks just generally look pretty cool.