If this is your first time hearing about the tuatara, you are not alone. This rare endangered animal is only found in one small part of the world, and there aren’t many of them left. So, you may be wondering, why are tuatara endangered? How many of them are left in the wild? And what threats do they face? Keep reading as we explore the answers to all of these questions.
What You'll Learn Today
How Many Tuatara Are In the Wild?
Tuatara are only found in New Zealand, and their numbers are mostly limited to some of its offshore islands. In fact, they were once thought to be extinct from mainland New Zealand; they have been reintroduced in limited regions, but no matter where they are found, their numbers are slim.
So, how many tuatara are left in the wild? The exact numbers are unclear and vary by source–they are generally thought to be between 50,000 and 100,000 individuals, though some sources report lower numbers.
Scientists report the number to be about 55,500 individuals in the wild, stating that there are more than that if you include those tuatara kept in sanctuaries and in captivity.
Why Are Tuatara Endangered?
As you can tell by the numbers above, there aren’t a lot of tuatara left in the wild. They are considered endangered simply because they are so few in number.
Also, as noted above, they are only found in New Zealand. Since they are not found in any other area on earth, they are more prone to suffering from habitat loss and introduced predators.
But perhaps you’re wondering, why are they only found in New Zealand? And why are their numbers so diminished?
Tuatara have existed for around 190 million years, a fact which shows great adaptability to a changing world. But, even though tuatara can adapt to cold temperatures and food shortages, they are vulnerable to other threats.
In short, they have survived a long time. But they are now facing threats that they have never faced before–threats of the modern world that they simply didn’t have to contend with for much of their existence.
Check out this video to learn more about the history and facts about the tuatara:
What Threatens the Tuatara’s Survival?
According to New Zealand’s Department of Conservation, tuatara face many threats in the wild. Some of these threats include:
Deforestation has led to the tuatara being forced from its natural home and losing its dependable sources of food and shelter. The more an animal is forced out of its natural habitat, the more at risk it becomes.
In addition to deforestation, natural phenomena such as forest fires can also deplete the tuatara’s natural habitat. Because they only live on a few small, scattered islands of New Zealand, even small habitat changes on any of these islands can cause major problems for the local tuatara.
Tuatara have been a federally protected species since 1895, and though these legal measures have limited activities such as poaching, such activities haven’t been completely eliminated. Tuatara are still occasionally hunted for meat as well as their hide.
Low genetic diversity
Many populations of tuatara are so small that the gene pool is extremely limited. What’s more, all tuatara populations are isolated from each other, so they are not able to interbreed and diversify their genes.
This means that the offspring produced are not as adaptable as they once were. A lack of genetic diversity makes them more prone to dying off as the earth changes rather than being continually able to adapt to changing conditions.
Rats and mice
Rats have perhaps been the single greatest threat to the tuatara. Not only do they practically eradicate the tuatara’s main food sources (insects and lizards), but they also eat tuatara’s eggs and young.
Rats are such a big problem that tuatara are only left in the wild on islands that have no rat populations. To protect these tuatara populations, efforts are made to keep rats from coming to these islands–to that end, humans are frequently forbidden from visiting these islands since rats may be present on boats and ships.
Mice are not as big of a problem as they don’t generally eat tuatara’s eggs and young, but they can limit tuatara populations by devouring their food sources.
Other introduced predators
Dogs, cats, ferrets, and other animals often kept as pets are predators to tuatara. If these animals are allowed to run free in areas with tuatara, they may kill and eat the reptiles.
Tuatara have the longest gestation period of any animal on earth–most only produce one batch of eggs every four years. Because of this slow gestation process, they cannot produce enough young to keep up with those being killed off due to habitat loss, predators, and the other threats discussed above.
Tuatara are endangered because there are so few of them left in the wild, they are only found in isolated pockets of New Zealand, and they face many threats. Some of these threats include rat infestations, low genetic diversity, and habitat changes.
What’s more, tuatara have such long gestation periods that they can’t produce enough young to compensate for the rate at which they are dying.