Is it a boy or is it a girl? For baby sea turtles it's not that cut and dry. Because they don't have an X or Y chromosome, baby sea turtles' sex is defined during development by the incubation environment. Warmer sand temperatures produce more females and cooler sand temperatures produce more males. A crucial step in the conservation of these animals is estimating hatchling sex ratios, which remains imprecise because of their anatomical makeup. Continue Reading... Use this thread to discuss the article above. What are your thoughts about Is it a boy or is it a girl? New method to ID baby sea turtles' sex?