Two 3D printed dummy eggs holding a nest at Mangawhai
Image: DOC


DOC and partners have achieved a breakthrough in endangered species conservation using 3D printed replica eggs to safeguard the nests of the critically endangered fairy tern/tara iti this summer breeding season.

Date:  21 March 2024

DOC used replica eggs as a management tool during high-risk periods such as storms and high tides, allowing the birds to continue incubating while their real eggs were temporarily held in incubators or moved to safety at Auckland Zoo.

Initially, DOC used hand-painted wooden eggs, followed by real eggs with hollow interiors filled with wax. However, these methods presented challenges as the eggs became fragile over time.

In 2023, with funding from the Endangered Species Foundation (ESF) Tāngaro Tuia te Ora, DOC commissioned Shaun Lee to produce 3D replica eggs, which were then hand painted by artist and marine biologist, Carina Sim-Smith. 

Real egg (left) and 3D printed dummy egg (right) used in tara iti nest protection.
Real egg (left) and 3D printed dummy egg (right) used in tara iti nest protection. Image: DOC | DOC

The replica eggs have undergone meticulous design considerations including shape, weight, UV resistance, size, colour, and texture. The success of the replica eggs has been pivotal in protecting tara iti nests, ensuring the birds continue their incubation without disruption.

The resulting eggs are so close to the real thing tara iti parents are completely oblivious when they were swapped out.

“DOC is really lucky to have the support of ESF to produce these 3D eggs which are a crucial management tool used to save tara iti. They allow us to improve productivity and save nests without losing real eggs in the process,” says Ayla Wiles, DOC Biodiversity Ranger, Whangarei.

Natalie Jessup, General Manager of ESF,  says: “It’s been so heartening this year to see the progress DOC, volunteers, community groups and Auckland Zoo have made to boost numbers of the tara iti.

“We were happy to see the replacement eggs were successful at holding nesting sites during risky periods when the real eggs were safely cared for at Auckland Zoo - they were so realistic parent birds had no idea they were not sitting on the real thing."

This success is part of a broader initiative to conserve tara iti populations, which has seen a record-breaking breeding season with 22 eggs laid and 14 chicks successfully hatched.

A dedicated team of tara iti DOC rangers and volunteers works year-round to trap predators, create safe nesting environments, and prevent disturbance near nesting sites.

The tara iti, once widespread, now breeds at only five main nesting sites from Auckland North: Papakānui Spit, Pākiri Beach, Waipū and Mangawhai sandspits, and Te Ārai Stream mouth. DOC collaborates closely with various partners, including Patuharakeke, Ngāti Wai, Ngāti Whātua o Kaipara, Ngāti Manuhiri Settlement Trust, Auckland Zoo, the Shorebirds Trust, the NZ Fairy Tern Charitable Trust, About Tern, Birds NZ, Tara Iti Golf Club, and the Waipū Trapping Group.

Generous support for the tara iti season has been provided by the Shorebirds Trust, Endangered Species Foundation, Pākiri Beach Holiday Park, Tara Iti Golf Club, Auckland Council, Manāki Whitebait, Tongariro National Trout Centre, and New Zealand King Salmon.


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