The sparrow with four sexes

Nature is so much weirder than people give her credit for. Anyway, if you're ever looking for cuter examples than lizards for your "actually sex isn't that simple" arguments, consider these guys?

Also, I choked on air reading this (in an otherwise touching piece):

In the early 1990s, however, it was too expensive and laborious to find answers by sequencing the bird's genome. So Tuttle initially focused on collecting more detail about their behaviour, such as how they selected mates and where they built nests. The goal was to understand what might affect offspring survival. She caught and tagged birds, drew blood samples and perfected the art of collecting semen. “Elaina was the best bird masturbator I ever met,” Gonser says.