Actually, due to the psychological and sociological nature of gender, there is only one extant animal species known to be able to change genders.
There's always room for further discovery. Dolphins & whales in general have very complex languages, dialects, and societies we barely understand. What I'm trying to say is we need to get Cetacean Ops on this to find out how many genders the dolphins have and if they trans them regularly.
Oh yes, I think it's entirely possible humans aren't the only ones with gender. Just the only known ones.
What about my hens that crow like roosters some mornings? They're not fertilizing each others' eggs, but they are adopting rooster-coded behaviors.
Wow, now the chemicals in the water are even turning the freakin' fish trans.
I found a YouTube link in your post. Here are links to the same video on alternative frontends that protect your privacy:
