For the third summer in a row, the street lights will go off in Punakaiki to help protect the endangered Westland petrel (taiko).
Waka Kotahi/ NZ Transport Agency and Buller District Council will switch off a 3.4km section of lighting through Punakaiki on State highway 6 as well as some side street lights, on Monday, November 7.
They will go back on once the tāiko fledglings have stopped their flights out to sea two months later on Monday, January 9, NZTA senior network manager Colin Hey said.
Petrels are sensitive to blue-green light and appear to be attracted to the LED street lights because of the similar colours.
The old sodium, yellow-toned lights in Punakaiki were replaced with LED, blue-toned lights four seasons ago after the poles corroded to the point of requiring replacement.
Soon after, reports of tāiko being found stranded near the new lights and invisible to drivers on the black highway surface started coming in to the Department of Conservation.
Given the endangered status of these birds, which only breed in the Punakaiki area, NZTA was keen to do whatever it could to help.
"It's a relatively small area with streetlights so the numbers of birds we're talking about aren't huge," DOC Buller acting operations manager Jacob Fleming, said. "But there's a strong indication that turning off the LED lights has made a real difference for the petrels.
"There was only one petrel found in the summer of 2017/18 at a residence in the area when the old sodium lights were still in use."
But in 2019, when the first four LED lights had been installed and turned on, six petrels came down on Punakaiki streets and one at a residence.
"When the lights were switched off for the first season in 2020-21 that number fell to just one down at a residence. In 2021-22 none came down in the previously lit area.
"Petrels are sensitive to blue-green light and prey on bioluminescent organisms in the ocean, which produce blue-green light. They are attracted to artificial lights because of the similar hues."
Punakaiki Beach Camp manager Craig Findlay supports the summer light switch-off and says people staying at his campground have no problem negotiating the footpath at night without overhead lights.
There is also a new footpath through the town making walking near the highway that much safer.
"The people we provide a shuttle service for, from Punakaiki to the start of the Paparoa Track in Blackball, are really interested in the petrel/tāiko story and appreciate the dark night skies."
The breeding colony is just south of Punakaiki, with petrel fledglings beginning to fly from early November.
The Westland petrel/tāiko fledglings or chicks nest in burrows.
The chicks, left alone in their burrows from an early age, will not emerge until they are fully grown and their parents have departed on their summer migration.
They head out to sea to feed. As they fly over human settlements, they can become disoriented from bright lights. This causes them to crash land nearby, a phenomena known as fallout.
"In the Punakaiki area, Westland Petrel Conservation Trust volunteers and DOC staff are on the lookout for downed birds during the fledgling season.
"Fledglings are easily disoriented by bright lights during their first flight out to sea and will crash land near the light source.
"Then, once grounded at an unfamiliar site they will not get airborne again without assistance. We carefully capture them in safe boxes and re-launch them over the sea from nearby cliffs," Westland Petrel Conservation Trust chairman Bruce Stuart-Monteath, said.
There has been no comprehensive study on the full extent of Westland petrel "fallout," he says.
"From my observations, it is likely that many more birds suffer from fallout but are never found, due to their nocturnal behaviour and hiding up in coastal bush during the day. People driving on SH6 between Punakaiki and the Waiwhero Creek Scenic Reserve, 5km south towards Greymouth, need to be particularly cautious.
"Anyone who finds a Westland petrel/tāiko wandering about, or even a dead bird, is welcome to contact us at 03 731 1826, 24/7."
The Department of Conservation says that today's breeding population of about 6200 pairs is a remnant of what would have originally been many hundreds of thousands. With only one breeding colony in the world, the survival of every fledgling to breeding age is needed for the survival of this species.
The main threats the Westland petrel/ tāiko continues to face are incidental bycatch in commercial fishing, introduced mammal predators, illegal releases of feral pigs into the breeding colonies and climate change, which alters prey availability and increases the frequency of severe weather events, which has caused the loss of breeding burrows to landslides in recent years.
Apart from the benefits provided to the petrels by the light switch-off, local residents and visitors to the area will also have the opportunity to see the night sky more clearly during this period.
