Loory evidently forgets that every duck is a girl duck. A boy duck is a drake. Loory’s story is about a drake that falls in love with a rock.
We’re used to regarding the male as the archetype for a species: lion, peacock, wolf. We used to do the same with our own species. That has become politically unacceptable, but apparently not in the case of ducks: Loory doesn’t identify his lovelorn duck as a boy duck. For him, duck is presumptively masculine, or perhaps a duck is presumptively male. (That’s an important distinction, but pursuing it would take us too far afield.)
With domestic animals, we’ve historically used as the archetype whichever sex was most useful or familiar to us, which was sometimes the female, as with cows and geese, except in cases where the immature (and therefore effectively sexless) animal is the one that interests us most: chicken, pig. (Though I gather that while Americans raise chickens, Englishmen raise hens.)
With several animals, both sexes are equally useful, so we have names for each that are separate from the name of the species: ram, ewe; stallion, mare; boar, sow; Tom, Moggie; Jack, Jenny. (I originally included hounds—dog, bitch—in that category, but the etymology of dog is mysterious, and although it is now used to designate males of other species, such as seals, I can’t prove that it ever referred specifically to the canine male.) Oddly enough, a thousand years ago, we did the same thing for ourselves in Old English: man meant a human being of either sex, while the male and female of the species were wer and wif, respectively. Wif survives as wife, but wer has almost disappeared. Its only remnant is in werewolf, where, paradoxically, it seems to mean human being, not merely male human being. (There’s also the archaic legal term, weregild, where, again, it seems to include both sexes.) Somehow, the generic term, man came to refer primarily to the male of the species, and only secondarily to the species as a whole; but that’s a topic for another day. (One would think that a term that applies to the whole species ought to be the specific term, while the generic term should refer to gender. One would be wrong. English is seldom simple.)
Nobody seems to have much to say about drakes anymore, or ganders, for that matter. I don’t know why.