Powerlines impact on the future of Blue Cranes
Powerline collisions could potentially tilt the population of Blue Cranes from stable, to declining.
That’s according to Endangered Wildlife Trust researcher, Christie Craig, at the Agulhas Biodiversity Initiative (ABI) meeting in September.
Blue Cranes are listed as Vulnerable to extinction on the IUCN Red List. The Overberg is a haven for the country’s national bird, with around half the population of remaining birds found here.
The vast powerline infrastructure in the Overberg and Swartland districts is reason for concern.
The vast powerline infrastructure in the Overberg and Swartland districts is reason for concern.
Christie says, “Big birds can’t manoeuvre quickly in flight, and therefore collide with powerlines. They also have lateral vision, so can’t see that well in front of them.” Wind and poor light also play a role. According to past research by UCT’s Jessica Shaw, in the Overberg, Blue Cranes are most vulnerable to powerline collisions, followed by Denham’s Bustards.
How viable is the Crane population?
Christie, an Overberg Crane Group board member, is currently undertaking her PhD research on the Blue Crane, including work to better understand the impact of powerline collisions. “I’m looking to understand how viable the Blue Crane population is into the future.” Research by UCT’s Julia van Velden found that the adult survival rate is 0.72 in the Western Cape. Christie says, “It should be at 0.81 for the population to be sustainable.”
Image left: Fitting owl devices
ACTION TO SAVE OUR BLUE CRANES
She’s now asking birders and nature lovers to get involved in helping the Blue Crane.
HERE’S HOW:
• Any powerline collisions can be logged on a smartphone application called WEP Incidents. This app is run by the Endangered Wildlife Trust.
“With this information, Eskom can place flappers on powerlines that are resulting in bird deaths,” she says. Eskom now also has access to flappers with red LED lights on them. These flash when the light is low, making them more visible.
• In a new citizen science project, she’s also asking birders to adopt a section of a powerline in the Overberg. The aim would be to walk this section once between December and May and record any carcasses. This information would also be fed back to Christie and the EWT, to support management actions to protect Blue Cranes.