Mostly spring/summer, I suppose, but I've had broodies hatch chicks in the winter too. I can't really remember if the cooler weather was any different in relation to pasty butt. But the hydration comment is interesting. I'll have to pay better attention. Thanks.
I get as many (actually probably more) chicks with pasty butt with broody hens as I do indoors. Brinsea brooder plate, heat lamps, etc. Personally I think it has more to do with heat/humidity combination plus each chicks own vigor. And even a little to do with breed. Some seem to get it more...
That comparison pic was my little assisted call duckling. When I left for work this morning, he was still alive. But he's in trouble. I worked his head free last night, and there's a lot of yolk to be absorbed. And he has some bill deformity. So I don't expect him to make it till I get...
I usually wait 24 hours from internal pip before making a safe hole. Teeny tiny hole, just enough to prick the membrane. But if done correctly, it can really be done any time after internal pip.
For mallard derived ducks, I wait at least 40 hours from external pip before even considering any...
It does look rather large relative to the shell, but I don't see any other obvious issues. Membrane looks good, inside the shell looks nice and clean (relatively lol)
I had a broody duck on 17 eggs. She quit after 2 weeks. I left the eggs outside for 2 more days, hoping she would go back but she didn't. So i brought them inside to throw away. They sat for a while longer and silly me put them in the bator. Several quit, but I cranked up the humidity last...
I make chicken saddles. But I haven't used any on my girls yet. My roosters aren't too rough on the girls backs, but seem to be harder on the backs of their heads! They need a bonnet or something.