What cute babies astrid.mary!! We raised our male duck from a baby and have geese too, so we are familiar with the water and mess issues. They certainly aren't anything like baby chickens.
So, does the temperature at which they are hatched affect what sex the babies will be? or is that just hit and miss?
We want females but realize that we will have to rehome or ahem, eat, the extra males.
And, where do you all buy your bators at? Our local TS store has some at certain times of the year but we've also seen them in all the hatchery catalogs too.
It is just hit and miss as far as gender goes, there is nothing you can do to alter that, sex is determined at time of fertilisation just like in human babies.
I actually bought my incubator off ebay, imported it from a seller in the USA as it was much cheaper for me to import one than to buy the same product in New Zealand! I got a really good package deal that included the pre-set Hovobator, auto-turner, temperature and humidity gauge, convertors for the NZ power grid, and egg candler and I am very happy with it.
What type is your boy duck?
Oh, I just read your little signature thingy that goes with your posts and see that he is a buff x runner. I don't know what a buff looks like - off to google one ...