Striking the wind beneath migratory birds’ wings
Migration – a basic need for millions of birds every year, often to escape inhospitable cold temperatures and to also reach new or fresh feeding grounds – requires large amounts of energy to travel thousands of miles. For this reason and others, birds have taken different geographic paths to make successful trips.
In particular, soaring birds, ones that have large wings or bodies and glide on warm air currents, use geographic or environmental conditions to their advantage. They have to fly mainly over land that offers optimal flight conditions, as water bodies and tall mountain ranges do not provide enough warm air currents (or thermal lift) during the day. So birds have located advantageous geographical spots that connect to form routes or flyways – such as the Rift Valley-Red Sea Flyway, used by soaring birds such as pelicans, storks, cranes and raptors to travel from Eurasia to Africa and back every year – to make successful cyclic intercontinental trips.
The knowledge of these routes has been passed from one bird generation to another for many millennia. However, our quest for more sources of energy to drive economic growth has, in recent decades, sometimes come into conflict with the millennia-old natural phenomenon of migration. In most of the countries in the Rift Valley-Red Sea region, hydroelectric power has been one of the main sources of energy. However, economic expansion has meant governments are tapping into other renewable sources of energy, such as wind.
Egypt, for example, already has operational wind farms along the flyway (including wind turbines at Zafarana and more will be constructed at Gebel al Zeit). Sudan, which in 2014, due to BirdLife’s intervention, replaced a power line that had electrocuted, perhaps, thousands of Egyptian Vultures with an insulated one, is assessing the possibility of installing a chain of wind farms along the Red Sea coast. It is for this reason that Sheikh Ibrahim, New Tokar, Saloma, Dungonab, Suakin, South Free Zone I and II as well as Darha sites are being studied.
Since wind is what keeps birds in the air and drives the wind turbines, it is unsurprising that migratory routes overlap with sites promising optimal power supply. Interactions between birds and poorly sited wind turbines are fatal to birds in many cases. In 2012, at the First Scientific Congress on Wind Energy and Wildlife Conservation in Spain, it was reported that the 18,000 wind turbines in the country could be killing six to 18 million birds and bats per year. Further, bird deaths per turbine per year as high as 309 in Germany and 895 in Sweden have been reported.
The most avian fatalities seem to be at turbines located on narrow migration pathways or near wetlands (bottleneck sites) where lots of birds congregate. The Rift Valley-Red Sea Flyway has many bottlenecks and it is used by about two million migratory soaring birds every year.
While we need more renewable energy to mitigate climate change and its negative effects, it is important that risks arising from interactions between birds and power infrastructure are properly considered. BirdLife is working with partners to develop tools that contribute to the development of renewable energy while mitigating biodiversity losses. For example, BirdLife has produced freely accessible guidance material, including a sensitivity mapping tool, through a GEF/UNDP funded project. The contracting parties to the Convention on Migratory Species have passed resolutions aimed at supporting safe power production and distribution from renewable sources.
The most important takeaway from this issue is that birds and human needs can coexist in harmony, if only we are willing to take a step back and look at the larger picture, and follow growth pathways that lead us to sustainable development.
Stichting BirdLife Europe gratefully acknowledges financial support from the European Commission. All content and opinions expressed on these pages are solely those of Stichting BirdLife Europe.