Tuatara facts, pictures & information. It may look like a lizard, but the tuatara is actually the sole surviving member of an entirely different group of reptiles.
The species is regarded by some scientists as being a ‘living fossil’ – a relic of the Mesozoic Era. Let’s find out more about this amazing animal ...
Tuatara Facts At A Glance
- Other Name(s): Beak-head, Cook Strait tuatara
- Scientific name: Sphenodon punctatus
- Type of Animal: Reptile
- Animal Family: Sphenodontidae
- Where Found: New Zealand
- Average Length: 61 cm (24 in), male; 45 cm (18 in), female
- Weight: Up to 1 kg (2.2 lb.), male; up to 0.5 kg (1.1 lb.), female
- Conservation Status: Least Concern
Other Interesting Tuatara Facts
- The tuatara keeps growing until it is around 35 years old, and can live to well over 100 years old. A 111 year-old captive male tuatara successfully produced a brood of hatchlings with an 80 year-old female!
- The tuatara has three eyes! Like many lizards and amphibians, it has a third, 'parietal eye' on the top of its head.
Meet The Tuatara: Introduction
The tuatara is the last living member of the ancient reptilian order Sphenodontia. (An order is a group of related animals.)
- You can find out more about animal groups such as 'orders' and 'families' here: Animal Classification
Sphenodontia split from the squamates (the reptilian order that contains lizards and snakes) around 250 million years ago. The order flourished from 200 to 100 million years ago, and became highly diverse; the pleurosaurs – a group of aquatic reptiles – were sphenodontians.
The tuatara itself is one of the most primitive of all reptiles and is sometimes called a 'living fossil'; an animal that has changed very little over a vast period of time. Both its brain and its gait (the way in which it walks) resemble that of an amphibian. The degree to which the tuatara has changed from its Mesozoic ancestors is debated by scientists.
The tuatara's name means 'spiny back' in the Māori language.
The tuatara has two subspecies: the Northern tuatara (S. punctatus punctatus) and the Brothers Island tuatara (S. punctatus guntheri). They live in different regions and were previously regarded as being separate species.
What Does The Tuatara Look Like?
The tuatara is the largest reptile in New Zealand. Males are around 61 cm (24 in) in length; females slightly smaller.
The color of the tuatara is variable, ranging from olive green and brown to grey and brick red. In addition, an individual’s color can change over the course of its lifetime.
Spiny crests run down the neck and the back. These are more pronounced in the male tuatara. The Brothers Island tuatara is considerably smaller than the Northern tuatara.
Where Is The Tuatara Found?
The tuatara is endemic to (i.e. ‘only found in’) New Zealand. In the past the tuatara was widespread across the mainland. Today the species only occurs naturally on around 32 small offshore islands in the Cook Strait (the area of sea that divides the North and South islands of New Zealand).
You can see this region in the map below. Zoom out to get a wider view!
The tuatara (including the Brothers Island subspecies, which was originally found only on one tiny island) has since been reintroduced to a handful of other islands.
In 2005 the species was also released into the fenced and closely monitored Zealandia Sanctuary on the North Island mainland.
The islands inhabited by the tuatara are typically rocky and exposed, and have sparse, stunted vegetation. The climate on the islands tends to be humid and cool with temperatures typically ranging between 7 and 24 °C (45 and 75 °F).
Colonies of breeding seabirds play an important role in these island ecosystems: by producing nutrient-rich guano they help support the invertebrate populations. These in turn form the bulk of the tuatara's diet.
The tuatara also uses the underground burrows of ground-nesting seabirds.
The tuatara is generally active at night. However, it will occasionally bask in the sun near its burrow.
Hatchlings are usually active during the day. This is most likely to avoid being cannibalized by the adults.
The tuatara prefers lower temperatures than other reptiles and remains active at temperatures around 5 °C (41 °F). Temperatures over 28 °C (82 °F) can be life-threatening for the species.
The tuatara sheds its skin frequently: juveniles up to 4 times a year and adults at least twice a year. The species can also break off and re-grow its tail.
Both sexes live alone in their burrows. Intruders are met with threat displays and biting.
Although the tuatara can hear, its ears are primitive and lack all external structures. Its eyes are able to focus independently of one other.
The tuatara, like many other reptiles and amphibians, has a parietal eye – a ‘third eye’ on top of its head.
A juvenile’s parietal eye is a translucent patch. The organ soon becomes covered with opaque scales as the animal develops.
The tuatara’s third eye is capable of perceiving light. It is thought that the organ plays a role in regulating activity cycles and / or body temperature. It may also help to produce vitamin D.
The reproductive cycle of the tuatara is among the longest of any reptile. Approximately 2 years passes between mating taking place and the young finally hatching from their eggs.
The tuatara reaches sexual maturity at some point between 10 and 20 years of age. Although male tuataras mate every year, females only mate every 2 to 5 years.
Tuataras are able to breed for many years. A 111 year-old captive male tuatara named Henry successfully bred with an 80 year old female named Mildred.
In the wild, mating takes place between mid-summer and early autumn (January to March). During the mating season the male tuatara becomes darker in color. He waits outside the female’s burrow; when she emerges he puts on a variety of displays. These include crest-raising, inflating the body and walking in a circle with stiffened legs.
Between 10 and 12 months after mating (from October to December) the female lays a clutch of up to 19 white, soft-shelled eggs in a nesting burrow. The eggs then incubate for a further 12 to 15 months, with development halting during winter. The sex of the hatchlings is determined by temperature. Warmer conditions produce more males; cooler conditions result in more females.
What Do Tuataras Eat?
The tuatara is a carnivore. It feeds primarily on invertebrates, including beetles, crickets, weta (a large cricket-like insect native to New Zealand), millipedes, earthworms, snails and spiders. Frogs, lizards, seabird eggs and chicks as well as juvenile tuatara also feature in its diet.
The single row of teeth in the tuatara’s lower jaw fits between the two rows of teeth in the animal's upper jaw. This arrangement helps the tuatara crush the tough exoskeletons of its insect prey. The tuatara is the only known species to have this type of jaw arrangement.
The tuatara’s teeth are fused to the bone and can't be replaced. Older tuatara with worn or missing teeth are required to feed on softer food like earthworms.
The slow metabolic rate (the amount of energy required by the body) of the tuatara means that it feeds less often than reptiles in general.
Is The Tuatara Endangered?
The tuatara is rated 'Least Concern' by the IUCN.
The species has been legally protected in New Zealand since 1895. In addition an active recovery program was launched in 1988. The total tuatara population is estimated to be between 60,000 and 100,000 individuals.
The main threat to the tuatara is non-native, introduced mammals (in particular rats). Together with captive breeding, the eradication of these species from the tuatara's island homes has been the main focus of conservation programs.
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