Ever wondered how, why and where our national bird moves each day? Well we do, and that is why the Endangered Wildlife Trust, in partnership with the International Crane Foundation have launched a project in the Western Cape to understand how Blue Cranes use and move within the landscape of the Western Cape. Cranes are one of the oldest family of birds alive in the world today and the Blue Crane is a near endemic to South Africa, with only a small isolated population of less than 60 birds found in Namibia. The rest of the world’s population of approximately 25 000 to 30 000 birds are found within our borders. The southern tip of Africa is home to at least half of the world’s population of Blue Cranes; which is astounding considering Blue Cranes occurring in the Western Cape is a relatively ‘recent’ spectacle. Blue Cranes first moved into the region when much of the natural fynbos and renosterveld, which characterised the Western Cape, were replaced with agricultural wheat fields and pastures.
The Blue Cranes adaptation to the agricultural landscape of the Western Cape is both a blessing and curse. It is a blessing in that farmers have coexisted with an increasing population of Blue Cranes for many decades and without doubt have significantly contributed to the growth and protection of our national bird. It is a curse as well in that climate change and socio economic factors may drive or direct changes within the agricultural sector of the Western Cape, which may make Blue Cranes vulnerable. In addition to this, an increase in wind farm developments and associated power line infrastructure could pose a significant threat to a population that is already heavily impacted on by collisions with power lines. We aim to improve our understanding of how Blue Cranes move and use the agricultural landscape of the Western Cape from roosting, to where they feed and breed. Through this we aim to understand why they use certain areas and therefore predict how potential changes in the landscape may influence or direct changes in the Blue Cranes use of the landscape.
In partnership with the Percy FitzPatrick Institute of the University of Cape Town, we have commenced with the fitting of satellite trackers onto adult Blue Cranes in the Western Cape. In August, we successfully caught four Blue Cranes in the Caledon area, under permit from CapeNature, and fitted the first of the fifteen trackers. More than two weeks since we fitted the trackers each bird is showing us a glimpse into their daily routine of moving from their evening roosts to foraging and in the future, onto and within their breeding sites. This research project will significantly contribute to our understanding of fine scale movements of Blue Cranes within the Overberg and Swartland region of the Western Cape, which will enable effective conservation planning within the province. Each bird fitted with a tracker is also fitted with unique combination of leg mounted colour rings that allows field researchers to visually locate them.
In addition to this, a student from the Percy FitzPatrick Institute, Julia van Velden, is completing her MSc research thesis on “Investigating the viability of Blue Cranes in Agricultural lands of the Western Cape: Survival rates and the role of farmer perceptions”. Julia has completed farmer surveys in the Overberg and Swartland regions of the Western Cape and is also analysing the Blue Crane colour ringing and re-sighting data to determine survival estimates and movements for the Overberg and Swartland regions. We look forward to sharing the results of this valuable research in our next newsletter edition.
Photo: The adult Blue Crane is released sporting it’s new high tech gear that will give us a glimpse into the daily activities of Blue Cranes
Thank you to the Table Mountain Fund for their support of this valuable project, as well as our project partners University of Cape Town’s Percy FitzPatrick Institute, CapeNature and the Overberg Crane Group.