Khaki Campbell, Best Guesses?

[Toad9000]

Just wondering if anyone has a good guess on the sex of my Khaki Campbells. Coming up on 6 weeks old and only one has a well defined quack yet (the one in the back). That particular duck has been the loudest and most vocal since day 1, so no surprise. I assume that its a hen, but the jury is still out. The rest all seem to exhibit a mix of both male and female indicating features to my untrained eye.

 

[JedJackson]

The surest way to tell gender in ducks is by voice. These may not yet have their adult voices, but if not they will within a few weeks. Females are actually the ones that have the louder quack, while males have a lower raspy quack, usually in a series. I'll post a link to show how to differentiate-- a search on the topic on Youtube will turn up more videos.