Durban – Birds that weigh just 17,9g each will determine the flight schedules at the new King Shaka International Airport after the project received environmental approval yesterday.

In its decision approving the R7,2 billion airport and trade zone, the department of environmental affairs and tourism set as one of the more than 80 conditions that “flight schedules must be planned around the flight times of the swallows”.

It is estimated that there are about 1,3 million birds in the vicinity in summer, presenting a possible obstacle for aircraft weighing several tons.

The barn swallows that migrate from eastern Europe every November to a reed bed in Lake Victoria at Mount Moreland, next to the airport site stay, until April. At dawn and dusk these birds form massive airborne flocks.

A study commissioned as part of the environmental impact assessment concluded that the barn swallows would not migrate to another area either during construction or operation of the airport.

Barn swallows can adapt to noisy environments and they show a high degree of philopatry, which means they return to the same roost year after year.

At the current Durban airport, swallows roost at a site between the airport and a petroleum refinery.

The study also found that the rate of aircraft and bird collision would not be as high as expected, therefore the effect on bird life would be low.

The study was based on radar equipment to monitor the birds’ behaviour imported by Airports Company SA, which would build the new airport. It estimated that the population of barn swallows was about 1,3 million, down from 3 million.

The government department’s decision also stipulated the careful management of waste water and other waste, to ensure it did not find its way into surrounding wetlands. Wetlands on site would need to be rehabilitated and maintained.

The department has also taken chameleons into account. All bush clumps to be cleared for construction were to be searched for chameleons, preferably at night and in weather conditions when they were most likely to be active.