Tough breeding season for tara iti - one of New Zealand's smallest birds

One of New Zealand's smallest birds remains in big trouble after a tough breeding season saw a third of the eggs or newly hatched chicks eaten by predators.

There were 29 tara iti, or fairy tern, eggs laid across the country, but only 11 chicks survived.

Despite the majority of eggs not fledging, Department of Conservation (DOC) tara iti recovery programme lead Alex Wilson told Checkpoint she remained upbeat about the numbers.

"We're feeling pretty positive about the season. We did lose quite a few this year, but we ended up with 11 chicks fledging this season, which is a good result for us.

"A bad year in the past, we could have gotten one to three chicks that might have fledged."

Wilson said predators remained the biggest issue for the tara iti, and DOC put a lot of effort in to ensure the chicks have every chance of survival.

The Mangawhai site had a "rat problem", and the Kahu, or Australasian Harrier, took out some of the chicks as well, Wilson said.

Wilson described the monitoring of the nests as "very intense", and said the breeding sites are monitored around the clock during the breeding season, which runs from September to February.

DOC staff and volunteers share the duties keeping an eye on the sites, and Wilson said they are looking for risk of predators, human disturbance, and any other threats like the tide and storms that might come in.

"If we perceive a threat, that's when we do things like collecting the eggs and taking them to safety."

WIlson said when the eggs need to be moved, they switch the real egg with a hand-painted 3D printed egg.

The real eggs are transported to either another safe nest, or to Auckland Zoo.

This season, 10 eggs ended up at Auckland Zoo, and a number of companies chipped in with fish to help feed the hungry chicks.

"They support us by providing us live fish, so trout and salmon, and the birds eat a lot so they can eat, when they're little, up to 70 fish a day. More than their own body weight," Wilson said.

DOC have also started tracking the birds, and after receiving some "cool results" last year, Wilson is hopeful the tracking will provide new insights into the birds.

Wilson said five birds have been fitted with satellite transmitters or "little mini backpacks", and DOC hopes to track them for a year.

"The information last year we'd never seen before, so it gives us insight into where they're going and areas that we might need to protect and other things that might be threatening them."

Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.