City lights throw rare firefly off his game

PUBLISHED : Saturday, 29 October, 2011, 12:00am
UPDATED : Saturday, 29 October, 2011, 12:00am


If you think your love life is tough, spare a thought for the poor Maipo bent-winged firefly.

The insect, a species only recently discovered and unique to Hong Kong, emits flashes of light to attract a mate.

But the firefly's call may get drowned out by the light from 2,000 flats that a property developer hopes to build near its habitat at Mai Po.

Yiu Vor, chairman of the Hong Kong Entomological Society, found that light pollution severely reduced the Maipo bent-winged firefly's chances of mating.

'The rare firefly uses its flash as a signal of mating. When the number of flashes is reduced, the chance of mating will also be reduced. This has a deep impact on their reproduction and survival,' he said.

The species was discovered in June last year in the mangroves and streams of the Wetland Park, 300 metres from a proposed development at Fung Lok Wai on Deep Bay, involving 19 blocks of flats 15 to 19 storeys high.

WWF-Hong Kong, which manages wetlands at Mai Po, signed a deal with Mutual Luck Investment in 2005 covering the development of the 80-hectare Fung Lok Wai site. Five per cent would be used for housing development, with the rest becoming a nature reserve with fish ponds and marshes.

Using a compact fluorescent lamp, the scientists enhanced the brightness of the habitat of the firefly from the normal 0.3 lux of light - similar to what people see during a full moon - to 0.5 lux.

They found that this reduced the bugs' number of flashes by half, from about 20 to nine per minute.

The property developer is conducting a study on the Fung Lok Wai project which it will submit to the Town Planning Board as part of the approval process.