Biology
Sexual Selection and Extreme Ornamentation in Birds-of-Paradise
Quick fact
In some birds-of-paradise species, males' ornamental feathers can be longer than their entire body, and these traits are driven by female choice—not survival advantage.
Why this is interesting
Imagine a bird with feathers so long they trail behind like a bride's veil—and males that dance upside-down. Why would such extremes ever evolve?