Speculating on Speculums

“That duck is nicely showing its speculum,” my birding teacher pointed out as we stood in the pouring rain at a garbage dump reclaimed as a Natural Area: what better way to spend a Saturday morning?

She didn’t say duck. She said the waterfowl’s specific name: Gadwall or Mallard or Wigeon.

But I couldn’t tell you which one she identified, because all I heard was SPECULUM.

“You can’t always see it when it’s at rest,” she added.

I should hope not.