Tuataras are much like other reptiles when it comes to caring for their young–meaning they don’t care for their young. That said, the tuatara is a unique creature, and there is much about its reproductive process that is unique as well. So, you may be wondering, how does a tuatara treat its babies? How do tuataras mate, how long does it take for the eggs to develop, and how many eggs do they lay? Keep reading! In this article, we’ll answer all of these questions and more.
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How Do Tuatara Treat Their Babies?
The tuatara is not known for forming close family ties. In fact, like many other reptiles, most tuatara babies never even meet their parents.
Young tuatara are on their own from the time they hatch from their eggs. They are completely self-sufficient and must depend on their instincts for survival.
And, when you’re a newborn, survival is no easy task. Baby tuatara are about 50 times smaller than adults, so they face many challenges and threats that the adults do not.
One of the biggest threats to these babies comes from their own species–some adult tuatara turn cannibal and prey on the young ones. For this reason, juvenile tuatara are generally more active during the day, when they can escape the notice of the nocturnal adults.
Baby tuatara mature very slowly, and they have much to learn and survive as they grow. Predators including rats, birds of prey, domesticated animals such as dogs and cats, and even some large and dangerous insects all present threats to young tuatara.
These reptiles don’t reach sexual maturity until at least 10 years of age, and sometimes as much as 20 years.
How Do Tuatara Mate?
Tuatara breeding season is in January, February, and March–mid to late summer and fall in New Zealand. Males and females begin interacting more during this time period, and males often become highly territorial, fighting with each other over areas or potential mates.
The tuatara’s mating ritual involves an elaborate physical display from the male: he erects the white spines on his back, puffs out his body to make himself look large and impressive, and struts confidently around the female. If the female walks away, it means that she is rejecting him; if she stays, it signals that she is accepting him and he will move in closer.
Despite that they have existed for millions of years, tuatara have very poorly developed genitalia. For this reason, the actual process of copulation is difficult and imperfect.
Tuatara mate by positioning their cloacae close to each other. This allows sperm to pass from the male into the female.
How Do Eggs Develop Inside a Female Tuatara?
Egg development is a multi-step process and takes an impressively long time.
Over a period of 1 to 3 years, the eggs slowly develop their yokes inside the female. Once the yokes have formed, it then takes an additional 7 months for the egg shells to develop and another 11 to 15 months until the eggs are deposited.
So, in total, it takes about 4 years from the mating to the laying of eggs since each step of development takes so long.
How Many Eggs Do Tuatara Lay?
Generally speaking, they lay about 8 to 15 eggs per brood, according to Brittanica. The eggs are generally soft and leathery, much like the eggs of most other reptiles.
Tuatara lay their eggs in sandy nests or burrows and usually cover them with a few inches of loose sand, dirt, or soil.
As noted above, mother tuatara do not stay with the eggs; they simply deposit the eggs and leave them to self-incubate. The babies must take care of themselves as soon as they emerge from the eggs.
How Long Do Tuatara Take to Hatch?
While the tuatara’s gestation period takes a long time, it also takes a long time for the eggs to hatch–another 11 to 16 months after their 4-year gestation. During the incubation period, baby tuatara fully develop inside the eggs, receiving warmth and nutrients from the soil to aid their development.
Since the egg shells are soft, they absorb water and allow nutrients and minerals to pass through them easily. The shells swell up like balloons as they absorb these elements.
Once the eggs are finally ready to hatch, the process is relatively quick and explosive, as you can see in the following video.
Why Does Tuatara Incubation Take So Long?
The eggs simply take a long time to develop inside the mother. For this reason, it takes a few years before they are even laid.
Then, once the eggs are laid, the embryos inside must continue to develop. This stage of development goes on hold during periods of cold weather, which can contribute to how long the process takes.
For example, during warmer years, the eggs may hatch within 11 months. During years with extended colder periods or unseasonably cool stretches, the babies may stop developing until it warms up again; in these cases, the eggs may not hatch for up to 16 months.
Because the incubation period takes so long, and the mother isn’t around to protect the nest, tuatara eggs are often discovered and eaten by rats and other introduced predators.
In fact, eggs are eaten and babies are killed at too quick a rate for the tuatara’s slow reproduction cycle to keep up. This is a major reason why the tuatara is considered an endangered species.
Tuatara babies are left to fend for themselves from the moment they are born. They grow and mature slowly, eventually reaching sexual maturity between 10 and 20 years of age.
Adult tuataras lay eggs just once every 4 years or so. It takes the eggs a long time to develop both inside the mother and after they have been deposited, and the reproductive process is often too slow to keep up with the number of tuatara eggs and babies that are destroyed by predators.