Tuatara Life Cycle

Referred to as a "living fossil", the tuatara (Sphenodon punctatus) may look like a lizard but is really a direct descendant of the extinct Rhinocephalia, a beak-nosed reptile from the pre-dinosaur era over 225 million years ago, according to the St Louis Zoo. Native to New Zealand, the tuatara boasts an amazing lifespan that tops 100 years. Its slow metabolism may be the reason why the tuatara lives so long; it breathes every seven seconds and can hold its breath for an hour.

  1. Mating and Eggs

    • The tuatara reaches maturity between 13 and 20 years. The reptile continues to grow until it reaches 30 years old, according to San Diego Zoo. Every four years the tuatara will breed. Breeding begins in March. Eight months later, the female tuatara lays up to 19 soft-shell eggs in a nesting burrow of sand. After laying her eggs, the female leaves.

    Incubation

    • Incubation takes 13 to 16 months, depending on the weather. During extremely cold weather, the growth of the embryos may be delayed. The eggs often fall victim to predators such as rats, so very few actually end up hatching.

    Sex

    • The soil temperature determines the sex of the embryos. If the soil is cool, the eggs produce females. Warm soil produces males. The embryos lack x and y chromosomes that determine gender.

    The Young

    • Once hatched, the babies must immediately seek food and dig a burrow for safety from predators. The reptiles enjoy feeding on insects and often steal bird eggs. Tuataras are opportunistic in their habits and will often co-habit a burrow with a sea bird instead of digging their own.

    Dangers

    • Rats and domestic dogs pose a serious there to the tuatara. In 1984, predation by rats drove an entire population of tuataras, which had flourished on an island off the coast of New Zealand, into extinction within six months. The rats killed adults, young and eggs. Currently the tuatara lives on only 30 tiny islands off New Zealand and is protected by the government.