KEY POINTS:
Restored land on the skirt of the Manukau Harbour at Mangere has seen a significant increase in birdlife which could help minimise possible bird strikes at Auckland International Airport.
Figures from the Ornithological Society show bird numbers are flourishing on Watercare land following the restoration of the Mangere
oxidation ponds about six years ago.
Counts of the wrybill, an endemic species named for its distinctive beak which curves to the side, have increased from 107 recorded in 1997 to 2000 birds last year.
There were also significant increases in the populations of pied stilts and bar-tailed godwits.
Ray Clough, a Mangere resident of 50 years, was thrilled to see the area return to what it was like before the oxidation ponds were formed.
He had always taken a keen interest in local birdlife and used to care for birds made sick with botulism from the ponds.
He works closely with Watercare in the habitat restoration work.
Mr Clough said the number of spoonbills, long-legged wading birds, had increased and the site had become a popular wintering area for them.
"Back in the 1980s you'd see the odd bird but recently there have been about 140."
Mr Clough was encouraged that the New Zealand dotterel, with a population of just 1700, had this year fledged four chicks in the area after recent stoat trapping. He said removal of the oxidation ponds and the return of tidal flows gave birds longer periods to forage in a vast feeding area. "The birds come from far and wide."
Watercare's general manager of operations, Craig McIlroy, said the oxidation ponds had covered an area of 500 hectares which was now returned to the coastline.
New beaches, bridges and bird roots have been built to create a habitat attractive to birds and helped keep them away from the airport where they could cause significant disruption due to the risk of bird strike.
"It is now a significant area from an ornithological point of view."
Watercare had planted around 300,000 native trees and built several bird roosts along the 13km of coastline next to the Mangere treatment plant.
Auckland Airport's airfields operations manager, Bob Parkinson, said Watercare should be commended on the work it had done to improve bird habitat, which could have a spin-off effect on controlling bird activity near the airport.
Mr Parkinson said the restoration work improved the feeding grounds, and the building of roosts on Watercare land encouraged the birds to stay in that area.
There were up to about five incidents involving problems with birds in flight paths which were mostly near- misses but occasionally bird strikes where they hit part of the plane.
He said the airport put a lot of effort into managing the problem including the employment of a wildlife hazards officer who used techniques such as noise scaring to keep the birds away.