One degree decides whether an alligator is male or female — and now scientists can predict it

An alligator mother cannot choose her babies' sex — the nest's temperature chooses for her. Around a pivotal warmth, eggs become females; a degree or two warmer, males. The trouble is that real nests heat and cool every day, so the old rules kept mispredicting wild clutches. A University of Georgia team — Karin Ebey, Christopher Smaga, Mathews Nascimento and Thomas Rainwater among them — has built the first model that predicts alligator sex while accounting for those daily swings, published in the Journal of Experimental Biology. As the climate warms, knowing what a nest will produce is how conservationists will know whether a population is tipping out of balance in time to help.