The fate of two bird species could help save others

Monitoring the outcomes of two Ethiopian bird species could help validate the predictive ability of widely used climate models, according to a new study from the University of Cambridge.

The White-tailed Swallow and the Ethiopian Bush-crow are threatened with extinction under similar circumstances. The birds are living in “climatic lifeboats,” with their tiny habitat ranges restricted on all sides by temperature and rainfall patterns. 

The experts report that, even under moderate levels of warming, models predict a severe loss of suitable climate for both bird species within the next 50 years. This will drastically increase their risk of extinction.

The research suggests that tracking the response of these birds to climate change will be crucial for preventing other species from going extinct in the wild.

Conservation measures such as assisted migration and captive breeding may be the only options available to safeguard the White-tailed Swallow and the Ethiopian Bush-crow now that climate change has eliminated their habitats. Understanding the birds’ ranges will inform conservation management plans for them in the newly formed Yabello National Park in Ethiopia.

“To find that two species are both limited by temperature at every edge of their global distribution is really quite remarkable,” said study first Dr. Andrew Bladon. “These completely unrelated species are influenced very similarly by aspects of the local climate. As the temperature rises due to climate change, they will struggle to survive.”

The researchers considered the potential impacts of future climate change projections from the Intergovernmental Panel on Climate Change (IPCC). These conditions ranged from the best case scenario – in which carbon emissions are reduced – to the worst case scenario with no change change in carbon emissions. In the worst case scenario, temperatures will rise by three to five degrees Celsius this century.

The experts found that, in all scenarios, both species are at severe risk of extinction in the next 50 years as the climate is predicted to become unsuitable for their survival.

The foraging ability of Ethiopian Bush-crows is impacted by temperature. The scientists expect them to start disappearing quickly once their range gets too hot.

The mechanism by which warming causes the decline of the White-tailed Swallows is not yet clear, but it seems to have a negative impact on breeding success.

“Climate change-driven increases in temperature are terrible for the long-term survival of these two bird species. But if they do go extinct in the next fifty years, they are at least a useful test case to validate climate models that inform a lot of conservation work,” said Dr. Bladon.

The study is published in the journal PLOS ONE.

–—

By Chrissy Sexton, Earth.com Staff Writer