Extremely rare footage of a tuatara hatching has been filmed at Victoria University of Wellington, an event that's part of a joint initiative to save this threatened population from extinction.

This egg was one of 23 being incubated in captivity on Hauturu ō Toi/Little Barrier Island, a nature reserve now home to around 300 tuataras.

"We never get to see the moment when they hatch because they do it in an incubator in the dark it just happens when we're not looking so to see it happen on film is very exciting," Sue Keall, a technician in the School of Biological Sciences at Victoria University, told ONE News.

Using a low-cost microcomputer and infrared camera, Keall and her team filmed seven hours of footage and then compressed it into a short video clip. The tuatara caught on video is the 255th to be hatched at Victoria.

The program, which has been ongoing since the early 1990s, is collaboratively run by Victoria University, the Department of Conservation (DoC) and local Mana Whenua Ngati Manuhiri, and partly-funded by The Hauturu Supporters Trust and Auckland Zoo.

Tuataras are a one-of-a-kind reptile only found in New Zealand. They resemble a lizard, but their closest relatives are an extinct group of reptiles around at the time of the dinosaurs, according to the San Diego Zoo's website. For this reason, some scientists refer to them as "living fossils."

The name "tuatara" is a native Maori word, meaning "peaks on back" or "spiny back," and is so named for the crest of spikes running along their backs. But their most interesting feature is their "third eye." Located on the top of their head, the eye may have a retina, lens and nerve endings, but tuataras do not use it for seeing. Scientists believe it helps the creature judge the time of day or season.

But these reptiles have been on the decline in New Zealand because of native Pacific rats, called kiore. Since kiore were eradicated from the island in 2006, juvenile tuataras hatched at Victoria have been able to be released into the wild on Hauturu ō Toi/Little Barrier Island.

"For the Little Barrier population, this program stopped their near certain extinction in the presence of kiore, and boosted their recovery by increasing the numbers more quickly than could have happened naturally," Keall said in a news release.

The tuatara caught on video is the 255th to be hatched at Victoria as part of the program.

[Credit: Victoria University of Wellington]