Project to move the red-billed gulls colony is believed to be New Zealand’s largest mass relocation of a bird colony

The building of infrastructure for the America’s Cup has forced the relocation of 1,000 at-risk seagulls in Auckland, in what is believed to be New Zealand’s largest mass relocation of a bird colony.

The project saw the colony of red-billed gulls moved from a space on Auckland’s waterfront that has been earmarked for a ferry terminal to be built for the sailing race, which will be held in the city in 2021.

Squawking, chip-stealing seagulls are under threat in New Zealand, with some colonies experiencing “unbelievable declines”, and others disappearing altogether over the past few decades.

Their chips are down: New Zealand seagulls under threat after 'unbelievable declines' Read more

Despite seeming to be in abundance because of their noisy antics and attraction to urban and inhabited environments, experts say the birds are severely at risk, with just 27,800 breeding pairs of red-billed gulls left nationwide, and the main offshore breeding colonies suffering population plummets of 80% to 100% since the mid-1960s.

Experts described the mass relocation of the gulls as “a bit of a gamble” and made them “uncomfortable”.

A team from Auckland council identified a new colony site 150m away from the bird’s previous home, and made the new site as attractive as possible.

The team installed 3D printed decoy gulls to attract the birds, carried driftwood and other familiar items from their old colony to their new one, and scattered fennel seeds and other coastal vegetation which had been present in their old home.

Tim Lovegrove from Auckland council said red-billed gulls are “notoriously itinerant” and display “plastic behaviour, making them fairly easy to work with as a species and more likely to adapt to a relocation”.

“The new colony was facing the sea, it was the same elevation and we made it look as similar as possible to their previous home,” said Lovegrove, who said the relocation made him somewhat “uncomfortable” as the best option would be not to move the birds at all, especially as they are an in-decline species.

“In August the first birds started to trickle back and happily landed around the decoys. Their nesting activity started through September and the following months and by mid January we had over 1,500 birds – so it was a hugely successful relocation.”

Environmental consultant Paul Kennedy said to his knowledge it was the largest mass relocation of a bird colony in New Zealand, and an important pilot as the country became increasingly urbanised, and coastal habitats were gobbled up for land development or by sea-level rise.

“They would sit on the fences next to the ferry terminal wondering where their home had gone too,” Kennedy said.

“But it didn’t take them long to find where the decoys were and settle down there. And bird numbers have increased so much we now have the same population as at the old site.”

The threats against seagulls are three-fold. Plunging fish stocks due to changing marine conditions and intensive fishing have meant less food for chicks. The conversion of coastal grounds to livestock and agriculture has threatened their natural breeding grounds, and introduced pests such as stoats and rats eating their young has further decimated an already vulnerable population.

Kennedy says despite the project being a success and the birds breeding habits being unaffected by the move, New Zealand needs to consider how wildlife living in urban areas will be protected, as cities grow larger, denser and more demanding.

“We have to protect the birds’ rights to breed and continue the population, particularly given the interference we have with coastal environments,” said Kennedy

“There’s a balancing act with trying to do the right thing with species like this and us”.