Saving wildlife all part of the job

NZTA earthworks managers working on the Waikato Expressway altered their construction programmes to allow the pied stilts to continue breeding in their construction site.

Two native copper skinks were released into a pest-free area in Mangaonui Gully to the east of Hamilton. Photos / Supplied

Construction teams working for the NZ Transport Agency (NZTA) have been protecting a colony of pied stilts (poaka) on the future site of the Hamilton section of the Waikato Expressway.

The birds began nesting in a ponded construction area that will become the Ruakura Interchange.

Up to seven adult poaka were there at one time, made two nests and laid seven eggs.

The birds and their tiny chicks continued to feed and nest as heavy earthmoving equipment operated in the landscape around them.

The species is currently considered at risk because of declining numbers and habitat destruction, so NZTA had a responsibility to protect the small breeding population in their construction site.

"Everyone was surprised when the birds selected a busy construction site to nest in," said NZ Transport Agency state highway manager Niclas Johansson.

"While it seemed a crazy location, the construction traffic may actually have protected the birds from predators such as cats and harrier hawks."

On-site managers of the earthworks altered their construction programme to avoid the birds' nesting areas while they raised their chicks.

The environmental staff on the project monitored the birds and nests, giving regularly reports to the Department of Conservation and the Waikato Regional Council.

The eggs hatched in December, but as the weather grew warmer heading into summer, the pond the birds were living around started to dry up.

When the site was checked in January before construction began, the adults and their chicks had left the site.

On the morning of Monday, January 16, NZTA also relocated two native copper skinks into a pest-free home in the Mangaonua Gully to the east of Hamilton.

This comes after three skinks were previously released in the valley, following extensive searching and spotlighting to save the lizards from areas that had been zoned for construction.

Johansson said that while staff working on the project had found hundreds of introduced rainbow skinks along the expressway route, the native skinks were relatively few.

The copper skinks are another threatened species, which are being out-competed by the rainbow skinks which are more prolific breeders.

Mangaonua Gully, which contains the pest-free enclosure, will be undergoing major restoration soon, as parts of the gully are currently populated with invasive plants.

The gully's 10.2 hectares will eventually be restored, involving 650,000 plantings and the introduction of additional native species.

Twenty hectares of gully habitat surrounding the sanctuary will also be subject to pest control efforts for 10 years after the restoration project has been completed.