These are the older two ducklings I've got now. I'm pretty sure we have one male and one female, but I've only heard hints of a quack so far, nothing close to sounding like the real deal.
I have 4 from my second batch in the brooder that are 2 weeks old that are about to be kicked out to live in the teenage coop, and another 7 expected to hatch this weekend.
Sadly, we went from 5 (2 males, 3 females) to 2 (one and one) in the course of a week, and my focus now is bringing my flock back up to size. I had one lost to a predator and that threw my flock all out of whack. I'd been keeping one duck that we'd been calling limpy who we got as an adult. She apparently had always had a leg issue (likely niacin, but I can't be sure.) She was kinda great to have around because she wouldn't wander far from the coop, and because of that, the rest of the flock wouldn't go too far either. She could still get around decently, even using the ramp to the hen house with no issue, but she would rather sit under her bush by the shed than forage with the flock.
Unfortunately, her limp made her a target for the drakes... 'affections.' And after the loss of one of one of the other females, they just targeted her more. She couldn't get away from them, and I had to cull the flock down to 2.
The only upside to this is that I did have eggs in the incubator from before the cull, so at least their genetics could carry on.