You Just Never Know...

...what science is gonna dig up. Take this, for example:

Ostrich penis clears up evolutionary mystery

"...there seems to be a strong correlation between genital size and bird mating habits. Emus, for example, pair bond, and the males have small penises. Rheas, on the other hand, have much larger phalluses and are promiscuous."

[---]

"“Darwin and others said that penises were primary sexual traits, meaning they’re essential for reproduction. But the birds say they’re not,” notes Montgomerie. Instead, he says, the penis may be a secondary sexual trait, helpful for stimulating the female, signalling reproductive fitness and even an aspect of competition among males — but not indispensable." (Emphasis mine)

Hmmmm. I think I'll stop there. But I beg to differ.