KEY POINTS:
A tiny population of New Zealand dotterels is benefiting from the construction of the Northern Busway near their breeding sites on the edge of the Auckland motorway, thanks to a range of conservation measures.
A unique project involving environmental agencies in co-operation with Fletcher Construction and Transit New Zealand has balanced the pressures of carrying out major site works with the challenges facing the endangered birds.
This has resulted in the breeding rates of the dotterel significantly improving, with six fledged chicks last year, compared with a previous average of just two a year surviving to a stage at which they can fly.
Work on the the Northern Busway began about four years ago involving major earthworks and structures.
Dave Slaven, who leads the ecology team at environmental consultancy company Boffa Miskell, was appointed to head a five-member group to advise how best to protect the dotterels and other birds, such as Caspian terns, in the area.
"Transit and Fletcher Construction really bought into the concept. They accepted the site was the home of an endangered species they could not ignore," said Mr Slaven.
For the first time predator control was introduced to tackle threats from ferrets, rats, mice and opossums.
But the major initiative to protect the bird population was to create new breeding sites.
Shellbank habitats were enhanced about 100m off the mainland coastal sites which the birds had been using for nesting near or on the motorway verge, just north of the harbour bridge.
Large volumes of shells and sand were used to build up what are known as the City of Cork shellbanks, named after a ship which beached there.
Five shellbanks were topped up so the mounds were above the reach of the high tide or storm surges to provide safe nesting sites.
Mr Slaven said some dotterels still wanted to nest in the construction zone, partly because there was not enough space for the territorial birds on the shellbanks.
He said they were not scared of the heavy machinery which was not perceived as a predator. They did, however, fear humans.
"As people walk along swinging their arms they can appear like flapping wings which makes the dotterels think of their natural predators, like black back gulls or harrier hawks."
Where construction workers discovered nests, the eggs were transferred to the Auckland Zoo.
RECYCLING REACHES INTO CONSTRUCTION ZONE
Safeguarding the dotterels is just one of several initiatives by Transit and project partners North Shore City Council and the Auckland Regional Transport Authority to make the busway project as green as possible.
Contractor NZ Strong is recycling as many materials as possible. Concrete dust is being recycled as mortar mix, and waste wood is being reused on site.
Silt filters prevent run-off from entering waterways and construction workers have even set up their own compost bin for food scraps.
Fletcher Construction, which was contracted to build the busway road, conducted a waste audit on the site and introduced new recycling measures that resulted in more than 70cu m of construction waste being diverted from landfill for recycling.
Mark Johnson, Transit's northern busway project director, said with the dotterels safely ensconced in their new nests, the busway project partners had focused their environmental efforts on air quality and recycling.
While the busway was not due to open until February 2008, Northern Express and other peak express bus services had already been operating for two years using fuel-efficient Euro 03 buses. Mark Lambert, ARTA's general manager customer services, said hundreds of commuters had switched from car travel to the Northern Express since the service began in November 2005, taking up to 500 cars off the Northern Motorway each day.
"That means a saving of more than 400,000 litres of fuel and a drop of more than 1000 tonnes in carbon dioxide emissions each year. Our research also shows people who catch the Northern Express are walking more, which is of course good for their health."
