The Blue Crane was listed as Vulnerable to extinction on the IUCN Red List, after numbers in the eastern grasslands declined dramatically. As cereal agriculture expanded in the Western Cape, Blue Crane numbers have blossomed.
This can also be attributed to the great efforts of farmers going out of their way to protect them, with support from the Overberg Crane Group and Endangered Wildlife Trust.
Still, these birds face many challenges in the agricultural landscape, like powerline collisions and disturbance during breeding.
At the moment, it’s uncertain whether the Western Cape Blue Cranes will continue to thrive, given climate change and expansion of power infrastructure to meet our growing human population.
Now we’re trying to answer some of these question.
Work by Sydney Davis and Julia van Velden gave us some fascinating insights into these issues, but much is still uncertain.
Christie Craig (Endangered Wildlife Trust/FitzPatrick Institute of African Ornithology) plans to provide clarity on these uncertainties through a three-year PhD research project.
This map shows the locations where chicks were ringed and released, the three bands indicate the colour ring combination on the right leg.
An example of the data that we receive from these trackers, once the Blue Crane chick began to fly, it moved locally around the nest site. Recently it made its first movement away from its nest site, a distance of just over 10 kilometres.
Bradley Gibbons and Anne Lacy about to release sibling chicks in the Swartland. The hood over the cranes eyes helps keep them calm while we fit the rings.
How do juvenile Blue Cranes move on a daily basis in the agricultural landscape? And when and where are they most at risk of colliding with power infrastructure?
To help answer these questions, Christie and the team fitted satellite trackers to Blue Crane chicks in February this year. Max Planck Institute designed 1000 of these trackers for crane species across the globe. So far trackers have been fitted to 12 Blue Crane chicks in the Western Cape and 11 Blue Crane chicks in the Karoo.
The trackers log locations as the bird moves and then sends the data to a central online database via the cellphone network. The tracker is a small black box with a solar panel, mounted on two rings that we clip around the leg of the crane. The design of these devices was tested extensively on captive birds at the International Crane Foundation. They found no harmful effects to the birds.
We fit the trackers on chicks shortly before they can fly. Once we catch a chick, we put a hood on its head. This keeps the chick calm. (In fact some chicks even have a nap while we fit the rings!) Each chick with a tracker also gets three colour rings on the other leg.