Vultures are large birds with very wide wingspans, as much as 2,65m wide, this means that they are at risk of electrocuting themselves on power lines as they can touch both live conductors at the same time. This is a huge problem on older power line structures where the danger to birds such as vultures was not known when they were designed and built and population density was lower requiring less infrastructure to support it.
As more and more people need places to live, wildlife like vultures are crowded out of areas where they have always lived; not only do they lose ground but also feeding and roosting sites. Vultures will always choose the highest ground for safety and also so that their exceptional eyesight can help them view their range and find food.
With some electricity pylons being as high as 20m, this is a lot taller than the trees that are in newly planted gardens, overgrazed Game Farms or well-populated Game Reserves and Parks particularly those with lots of elephant.
The Cape Vulture especially uses the pylons to roost on, research has also shown that they use the power lines to make their foraging ranges bigger by using the pylons as “safe” roosting sites as they extend their travels; a bit like us staying at hotels along the road when we go on holiday far away from home. This increased amount of time spent on or around the power lines has increased their chances of being electrocuted or injured in a collision with the cables.
How do we make a power line safe for large birds like vultures?
- The gap between the two live conductors must be so wide that the birds can’t touch the two conductors at the same time.
- Improved design and better materials
- Bird Flappers to make the thin earth wire that is seen above the main power cables more visible to birds.
- Bird flight diverter spirals which are also used to make the lines more visible, they are more stable than the bird flappers
- Nocturnal “OWL” device which make the structures visible to nocturnal birds – this is still being developed but is an exciting option for the future.
- Insulating sleeve to prevent the vultures from making contact with the live components, it is a large black cover placed over the live terminals.
Mitigation (making these structures safe) is expensive and time consuming and does require specially trained people to do it safely, even so it is very important that the power lines close to breeding colonies and feeding sites are made safe and bird friendly, vulture numbers are so low that extinction is a very real threat without our intervention to save them.