
Image via kevinzim, Creative Commons
Yes! The weather has everything (literally) to do with it. Some reptiles, including crocodiles, don’t have sex chromosomes (those Xs and Ys involved in the determination of the sex as well as the development of sexual characteristics). Whether a croc hatches as boy or girl is not a genetic lottery – it’s a climatic one (what scientists call temperature-dependent sex determination). If the temperatures surrounding the nest are very high or very low, the embryos will be female. Anything in the middle (between 31-34°C) will mean crocodile males are on the way.