I'm sorry to hear about your duck! I know even rodents can attack them, at least we had a large rat come into the chicken coop one night, I had forgotten to close the door, and I hear this racket, run over to find something had dragged some of my guineas out of where they were and through a wire enclosure. It sounds like a predator to me. :(

Sorry to hear its missing. Does your pool still have a filtering system in it? Ya you said its turned into a pond but could the duck swam into it and got itself caught in there?? Best of luck.

S.

Hmm a rodent could be possible, I've seen some large rats in my garden before. Though she disappeared at around 11 am when most predators are asleep so i'm not sure. The pool filter has a wire mesh covering it, so I don't think it could have gone in there.
Sigh, I think I have accepted that she's gone. My remaining duck seems ok, still eating and swimming happily. Do you think it's cruel to keep a duck alone with no company? I was thinking of getting another but I'm afraid it will go (unexplainedly) missing again.

I would get another duck, as long as they get along with each other, that would be nice, your duck might be lonely.