I've read this three times and hope I have everything straight. Just a few comments I hope will help, but I'm also hoping others will chime in. I know a good bit about ducks, but there are others here who know far more than I do.
As far as your Pekins potentially being mules, this isn't possible unless everything I've ever thought I knew about mule ducks is wrong. All Muscovy/Mallard descendent ducks are sterile since they're different species even though they're all ducks. Mule hens don't even lay eggs. Hinny hens (the opposite cross) can lay eggs, but they are never fertile. This means yours can't even be hinnies because they wouldn't have been alive for that three weeks you mentioned.
I do completely understand the not wanting to be let down part, but you have to remember that, if they're not alive now, they're not going to be alive later, either. It's better to know and to go ahead and dispose of any infertile eggs or eggs with dead embryos. I don't incubate, but that's true of whether you incubate or do natural hatching. Eggs without living embryos will start to decay and build up bacteria. That's a mess to clean out of a nest, and probably not easy with an incubator, either. If you're the least bit uncertain after candling, just put them back in and wait another few days or a week.
You didn't mention how you do your candling. Can you let us know what method you use?
Best of luck!
Thanks for chiming in. I did post multiple times about mule females and my drake, my question being, would the eggs get fertilized at all if they were mules or infertile with each other? I didnt think an embryo would begin to grow at all in that case. No one knew enough to really get into the nitty gritty of it.
That first year it was Syanne the pekin, Ephinny and Varia who are part pekin (and I dont know what the other part is) and Wist and Piper both pacific blacks. I never saw Wist mate anyone, but I know for certain he is male, (seen his penis) BUT I see those 3 big girls mating each other all the time. Each take turns on top. Only Ephinny never sits on eggs. When I started checking the eggs a good 50% were fertile, but I had no garuntee it was actually WIST doing it! Syanne kept a horrid nest. Let everyone lay in it and try to sit on 50. Stay on them in blistering heat, abandon them in cool weather. Varia was much better but hers still died. I was devastated over Pipers nest, I didnt even know she had one until I found her eggs kicked around. At that point I was cracking at least 2 eggs a day and I always saw a fertilized spot, sometimes even a split nucleas.
The next year with the incubator I was sure all was well. I never saw the really clear viens you want to see, nor the red hue (it was more orangey) but a dark cloudy ness that increased and at about 2 weeks was pulsing like a heartbeat. Continues to grow promisingly to about 3 weeks then bam, dead halt, rotten eggs. Literally a couple of days from the moment I think Ive got a live duckling I get a cracked stinking rotten egg.
I use a bright torch and a cardboard toilet roll. I hold the roll firmly against the torch and in a dark room hold the egg on the end of the toilet roll. I gently turn it a little to get the light through the air sac.
The 2 successful incubations I did WITHOUT an incubator. I got Wist because my mate did land clearing and found the eggs under an earth mover and 'thought my ducks might just sit on them'. I rigged up a box and a heat lamp and didnt touch them for 2 weeks and Wist up and hatched himself, no turning, no humidity. Piper was a similar story of rescued eggs, I rigged up a homemade incubator and misted and turned and candled all the time! I had 5 eggs and 3 looked like they were developing well. Only one 'jumped' when I candled, and I believe that was Piper.
Ok, so, if everyone has babies this year, what is wrong with Wist? Even now, with the 2 call drakes mating everything that moves he occasionally gets excited and pulls his girlfriends tail...But thats it.I have another thing going on with the call drake that cant be a drake, but thats another story.
You make a fine point. I'll try and find time to candle tomorrow.