Exactly why when I first read it I didn't give it much thought. I thought sex was determined at fertilization so timing and temperature would not matter. I also agree, the egg industry would have perfected this.This is misinformation that has spread, they aren't like turtles where temperature decides the sex. Birds have clear sex chromosomes with females having ZW and males having ZZ. Once a bird egg has been laid chromosomes don't just randomly change shape completely. Also if this was true don't you think the egg industry would just stop hatching roosters so they don't kill them at 1 day old?
When Perris wrote "I don't rush to let them brood as I (and others) have found that earlier broods typically have more males and later broods have more females."
My first thought was earlier hatches would be during cooler weather, later hatches would be during warmer weather. I was just interested in his or others experiences.
