Tuataras Slow to Mature

In most cases, the tuatara — a spiny-backed reptile in New Zealand — does not reach maturity until at least 15 years old, and it’s eggs take 12 months to hatch. During that time period, temperature is important because it determines gender. Eggs incubated at 21 degrees centigrade produce an even number of males and females. If the temperature is raised just one degree, nearly all the young will be male. Lower the temperature to 20 degrees, and the hatchlings will be female.