We normally associate high testosterone levels with male dominance and aggression. Among ruffs – a shore bird that breeds across Europe and Asia – some males suffer from too much of it.

COLUMN. A German team discovered that some males don't produce testosterone but instead breaks it down, making this bird a symbol of sexual diversity.

(A) Male ruff ... [+] morphs differ in ornamental plumages ... “Faeders — the female mimics — are small birds, just slightly larger than females and smaller than the other males, that ...

Markku Nikki (Finland) highlights the impressive jumps and flamboyant plumage that are part of the male ruff’s mating display ... This time, the fighting was quiet but intense. The birds’ rapid ...