Why the lights on Auckland's Sky Tower and Harbour Bridge aren't shining so bright

Light pollution from across Auckland has been disorientating juvenile seabirds, and in the past few years, they have been crashing-landing inland and becoming grounded.

Seabirds need high points, such as a cliff to launch from, so once on the ground in an urban area, it is very difficult for them to take off again.

Many of the grounded seabirds which are brought to the native bird hospital BirdCare are Cook's petrels or tītī, which are a smaller petrel species that fledge during Autumn.

BirdCare fundraising and advocacy manager Rashi Parker said it had admitted 26 grounded Cook's petrels in the past two weeks, slightly fewer than usual.

There had also not been any found in Auckland CBD, which was usually a crash hotspot.

Parker said bright LED displays were particularly problematic for the birds. In 2019, the number of lights on the Sky Tower doubled when SkyCity switched to LED lighting.

But she believed recent changes made by SkyCity and Vector to their LED light displays were helping.

"Last year, thanks to RNZ, we were actually able to connect with SkyCity, which is responsible for the lights on the Sky Tower, and Vector Lights, which is responsible for the lighting of the Harbour Bridge.

"Both groups were really responsive and committed to reducing their public display lighting by 50 percent during the key migratory seasons."

Cook’s petrels being released at Piha. Photo: Supplied / Simon Runting

SkyCity confirmed that it was dimming the Sky Tower lights and minimising the use of short-wavelength colours, such as blues and violets, from February to June, to reduce the impact on the Cook's petrel.

Vector Lights said the Harbour Bridge lighting had operated at 50 percent intensity during the peak migration season for seabirds since 2018.

They said after feedback from BirdCare and Auckland Council, it was extending the period the lights were dimmed from three months to six, from 1 January to 31 June.

But Parker said there was more to be done to help the endemic tītī, with Henderson and Māngere being hotspots for rescues.

She wanted large apartment complexes to dim their lights and choose more bird-friendly, warmer colour spectrums.

BirdCare hospital manager Pooja Doorle said she was still busy looking after fledgling Cook's petrels, which mainly bred on Little Barrier Island and Great Barrier Island, but had found themselves grounded or injured elsewhere.

A fledgling Cook's Petrel being given a bath to restore its waterproofing. Photo: RNZ / Jessica Hopkins

Staff like Doorle bathed and assessed the birds to make sure they were in good nick before releasing them at Piha.

From April to May last year, BirdCare admitted about 100 fledgling Cook's petrels. But only about 60 percent were released, with many injuring themselves after landing in unfamiliar environments.

Rashi Parker said if people spotted a Cook's petrel where it did not belong, they should bring it to BirdCare or another native bird hospital in a ventilated box, or call the Department of Conservation's 24/7 hotline, 0800 DOC HOT (0800 362 468).

"Typical spots would be under street lamps and brightly lit buildings. People have found them under the downtown car park, because these are burrowing birds, and I suppose the downtown car park is a bit like a burrow."

She said while they could be mistaken for seagulls, Cook's petrels had distinctive tube noses.

Many of those helping rescue fledgling tītī and other seabirds, including at BirdCare, were volunteers.

Karen Kermadec from the Seabird Trust, who is on DOC's Wildlife Response Squad, said it was tough but important work.

"It's often heartbreaking for the volunteers because some of the birds are already injured. They may not survive long enough to get them to the BirdCare centre or to a vet."

Cook’s petrels being released at Piha. Photo: Supplied / Simon Runting

She said the trust working with DOC to, in the future, start banding birds who became grounded and then were released after rehabilitation.

"At the moment you release a bird, but you have no idea whether it's going to survive or not.

"So is this effort worth it? I think it's certainly a question that needs to be asked."

Chris Gaskin from the Seabird Trust said people should also keep an eye out for other seabird species, which had been found in people's gardens and other unusual places.

"In Auckland, little storm petrels are also being drawn into the lights in the city. These birds are breeding in places like the Noises, quite close to Auckland.

"With any wild bird, it's a case of getting hold of DOC and making sure it gets checked out and released in a safe place."