Source: New Zealand Transport Agency
For the third summer in a row, the highway lights will go off in the West Coast town of Punakaiki to help protect an endangered seabird.
Waka Kotahi NZ Transport Agency and Buller District Council will switch off a 3.4km section of lighting through Punakaiki on SH6 as well as some side street lights to help protect the native Westland petrel/tāiko.
The lights will be switched off on Monday, 7 November and back on once the tāiko fledglings have stopped their flights out to sea two months later – on Monday, 9 January, says Colin Hey, Senior Network Manager for Waka Kotahi.
Petrels/tāiko are sensitive to blue-green light and appear to be attracted to the LED street lights because of the similar colours, says DOC.
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 DOC.
Given the endangered status of these birds, which only breed in the Punakaiki area, Waka Kotahi was keen to do whatever it could to help.
DOC’s bird counting data
“It’s a relatively small area with streetlights so the numbers of birds we’re talking about aren’t huge,” says DOC Buller Acting Operations Manager Jacob Fleming.
“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.
“In 2019, however, 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.”
Pedestrians and the local campground
Pedestrians, who are the main beneficiaries of the highway LED lights, are advised to take extra care at night during this time with cautionary signage being installed on either side of the highway affected.
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.”
Why do these birds aim for the road not the sea?
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, attracted to the bio-luminescent ocean life. As they fly over human settlements, they can become disoriented from bright lights (particularly with the blue tones) under their flight paths. 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,” says Bruce Stuart-Menteath, Chairman of the Westland Petrel Conservation Trust.
“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.”
There has been no comprehensive study on the full extent of Westland petrel “fallout,” he says. “The precautionary principle should apply. 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, 5 km 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 7311826 24/7.”
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. (Photo: Bruce Stuart-Menteath)
Young Westland petrel/tāiko affected by fallout/ disorientation waiting to be relaunched by the Westland Petrel Conservation Trust. (Photo: Bruce Stuart-Menteath)
A Westland petrel/ tāiko preparing for take-off from the bush towards the Tasman Sea. (Photo: Bruce Stuart-Menteath)
A fraction of the original numbers surviving
The Department of Conservation/ Te Papa Atawhai says that today’s breeding population of about 6,200 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, says DOC.
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.
