Ambient temperature can influence the sex of reptile embryos, but turtle embryos may move to warm or cool spots inside the egg to counteract the effect
Source:
https://www.newscientist.com/article/2211976-turtle-embryos-may-control-their-sex-by-moving-inside-their-eggs/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home