This has been some really interesting information. Thank you!
@MGG if vent sexing is easy and safe on adult ducks, I'd be really grateful if you could teach me how to do it. I'd love to figure this duck out.
I agree with Shaw that Jax does sound more like a juvenile drake, but he seems to have more voice than I've ever heard from any other drakes. I'm just so confused about this duck. He's sounded this way the entire time I've had him. I expected changes like I've always seen in ducks. My Pekin drakes were slow to mature and one kept his quacky hen voice for a long time, but not this long. I'd be absolutely over the moon if he just matured overnight because even though his bill color isn't right, his body is really nice and he/she is a really sweet duck. Jax is in his own coop and run for now. He is in between a flock of Calls and a flock of Aztec's so he still has the company of fellow ducks.
If a hen suffers from a damaged ovary, does her voice remain the same as her plumage changes or is there some changing to more of a raspy drake like voice?
I really hope Jax is just super slow to mature. The breeder suggested that maybe he is just shy and that explains why I've not witnessed any mating behavior, but after listening to the voice recording, the breeder isn't so sure.
Thank you again for these informational replies! If I figure this duck out, I'll be sure to update. I'd love to hear anything else anyone thinks of