I had read somewhere and can't remember for the life of me where but that the temperature the eggs are kept prior to incubation effects the boy : girl ratio when they hatch. If that's true, then it would seem that eggs laid/stored during cooler temperatures have a greater chance at becoming females.
The only egg I've ever tried to hatch turned out to be a male: hatch day 6/8/14 after it sat on my kitchen counter for a week prior to being put in the incubator and I don't remember what the temps were like then but I do remember it being very sunny so likely rather warm in my kitchen. There were two other chicks that hatched during that incubation from another keeper (in my son's kindergarten class) and at least one is female (whom I also have). The third chick was a silkie and I have no idea what it turned out to be or any details about how long it had been from lay date to incubation for those two chicks.
There are so many variables to a study like that but it would definitely be an interesting one to undertake!
That's not for birds but for reptiles.Egg can be stored as cold as 40 degrees for up to 15 days and then their viability drops after the 15 days.
In N.H.,Tony.