Two tuatara hatchlings sighted at Orokonui Ecosanctuary are the first to be seen since adult tuatara were released at the ecosanctuary in 2012.
Possibly be the first tuatara to hatch as part of a viable tuatara population in the South Island – Te Wai pounamu for several hundred years, the creatures were found earlier this year by University of Otago researchers.
Undergraduate student Jade Christiansen, who was working on a Te Ngaru Paewhenua: Maori and Pacikfic Science Summer studentship, spotted the hatchlings under small strips of roofing material.
“My hands were shaking” Ms Christiansen said.
“I was very nervous, yet very excited. The hatchlings can be surprisingly lively.
“One of them still had its horny ‘shell-breaker’ – a projection on the tip of its snout – so I knew it had hatched recently.”
Professor Alison Cree, of Otago’s Department of Zoology, leads the group that has been researching the tuatara population for more than seven years.
A recent Masters student, Jemima Gardiner-Rodden, had been monitoring the nest for more than 16 months.
Ms Gardiner-Rodden said it was likely the hatchlings were female due to the long duration of incubation in the nest and the relatively cool soil temperatures.
Nest temperatures are known to determine the sex of developing tuatara embryos.
Further evidence at the nest, such as empty eggshells with distinctive splits , suggests there may also be additional hatchlings from this clutch. Female tuatara nest only every few years and average-sized females lay a clutch of about nine eggs.
Orokonui Ecosanctuary conservation manager Elton Smith said the discovery was another significant biodiversity outcome for the sanctuary.
“This success can be directly attributed to our fence that excludes all introduced mammals (other than perhaps mice) that would otherwise predate upon the tuatara,” Mr Smith said.
Professor Cree said evidence of offspring being produced was an important stage to reach when re-establishing a viable population, and that a breeding population at Orokonui could be a valuable contribution to protecting the survival of this taonga species in the global climate emergency.
“We’ve been excited to see tuatara surviving and growing, and we’ve long suspected that hatching was occurring based on indirect evidence, including split eggshells,” Professor Cree said.
“But this is the first direct evidence for the entire cycle through to hatching, from egg-yolk production onwards in the mother’s body, taking place at Orokonui.”
Nelson-based Ngati Koata are kaitiaki (guardians) for the source population of tuatara for Orokonui, and Kati Huirapa Runaka ki Puketeraki as mana whenua are tangata tiaki for the ecosanctuary.
“We’re thrilled for tuatara, for Orokonui and for our iwi partners who’ve been so supportive of this project,” Professor Cree said.
Orokonui Ecosanctuary is currently closed due to Covid-19 but staff are still carrying out essential tasks.