Eskom has lit up the night, albeit with only a ”dim flicker”, at a farm dam in the Western Cape’s Overberg in a bid to stop blue cranes flying into nearby power lines.
The power lines, on the farm Hillside near Caledon, have been responsible for the deaths of at least 30 of the elegant birds in the past eight years.
Eskom workers last week attached fluorescent light tubes to the lines, to make them visible at night.
Chris van Rooyen, manager of the Endangered Wildlife Trust’s strategic partnership with Eskom, explained on Tuesday that as many as 50 blue cranes roost at night in the shallow water of the dam.
They are skittish, and if disturbed take to the air, even in the dark, and risk blundering into the power lines.
It is the impact of the collision, rather than the 11 kilovolts of electricity flowing through the lines, that kills them, Van Rooyen said.
The fluorescent tubes are simply hooked on to the lines, and the ambient electric field makes them glow constantly with a ”dim flicker” — enough to create a line of light for the birds to avoid.
The bulk of the tubes will also make the lines more visible for the birds in the daytime, he said.
The idea of the warning tubes is a South African invention, and they have already been put to use at a site off the N1 near Paarl to protect pelicans, and at the Sua Pan in Botswana, for flamingos.
Van Rooyen said the Overberg project is being run in conjunction with the Overberg Crane Group, which plays a major role in monitoring mortality, and Cape Nature Conservation.
The blue crane is South Africa’s national bird, and occurs only in Southern Africa.
It is listed as ”vulnerable” on the World Conservation Union’s red data list after a dramatic decline in numbers in the past three decades.
There are estimated to be about 21 000 in South Africa and small populations in Namibia and Swaziland. — Sapa