Africa's 'Green Corridors' Can Save Climate-Stressed Birds

Led by biologists at Durham University, the computer modeling study probed the effects of "moderate" climate change on 815 bird species of conservation concern in sub-Saharan Africa and on the network of sites designated for them, known as Important Bird Areas.

The findings suggest that it is up to African legislators to protect ecosystems that can serve as what the scientists call "green corridors" to help wildlife find new, more comfortable areas when their habitat heats up. More than 40 percent of African Important Bird Areas lack any form of legal protection under national or international law.

A globally-threatened Shoebill stork, Balaeniceps rex, in Uganda's Mabamba Bay wetland (Photo courtesy Ramsar)

"Important Bird Areas will provide new habitats for birds that are forced to move as temperatures and rainfall change and food sources become scarce in the areas where they currently occur," said Dr. Stephen Willis from the School of Biological and Biomedical Sciences at Durham.

Published in the journal "Ecology Letters," the study found that over the next 75 years, climate change will affect the species of some regions more than others.

"The central regions of Africa should maintain many of their current species as long as the protected areas remain intact," Willis said. "By contrast, areas of the Afrotropical Highlands, which occur in countries such as Cameroon, South Africa and Ethiopia, will see enormous change with more than 40 percent of species leaving."

The researchers looked at a network of 863 Important Bird Areas across 42 countries and territories covering around two million square kilometers (1.3 million square miles), about seven percent of the African continent.

The sites are identified as being critical for the conservation of bird species that are globally threatened, restricted in range or to particular environmental conditions.

"The results show that 90 percent of priority species in Africa will find suitable climate somewhere in the network of protected areas in future. However, one in 10 birds will have to find new places to live and breed so new sites will have to be added to the IBA network," Willis said.

The scientific team included researchers from BirdLife International and the Royal Society for the Protection of Birds, RSPB, which is the BirdLife partner in the UK and funded the research.

Dr. Stuart Butchart, global research coordinator at BirdLife International, said, "The survival of much of the planet’s biodiversity under climate change will depend upon adequate protection for biodiverse ecosystems, the IBAs within them, and support for the people who depend on them - so that local communities can participate actively in making their environment more resilient."

"It is essential that policy leads to adequate protection of IBAs and takes account of the critical role that ecosystems play in helping wildlife and people adapt," he said.

Ruth Davis, head of climate change at the RSPB, said, "Looking after IBAs is vital for the future of our wildlife. Protecting the natural resources and services provided by these ecosystems is vital for people too. Healthy ecosystems are the first line of defense against the impacts of climate change for many of the world's poorest people."

A separate study by Durham scientists released today shows that marathon bird migrations from Africa to Europe and Asia are likely to get even longer as the climate warms.

"The predicted future temperature changes and the associated changes in habitat could have serious consequences for many species," said lead author Nathalie Doswald of Durham's School of Biological and Biomedical Sciences.

A common whitethroat, Sylvia communis, in Cambridgeshire, England (Photo by Katie Fuller)

Some 500 million birds are estimated to migrate to Europe and Asia from Africa. Birds weighing as little as nine grams undertake the annual migration of thousands of miles between the two continents to find food and suitable climate.

This first-ever study of the potential impacts of climate change on these migrations shows that some species may have to fly as much as 400 kilometers, 250 miles, farther as the climate warms.

Funded by the RSPB and the Natural Environment Research Council, the study looked at the migration patterns of European Sylvia warblers, a group of birds that are common residents and visitors to Europe, like common whitethroat, Sylvia communis, and blackcap, Sylvia atricapilla.

"Most warblers come here in spring and summer time to take advantage of the surplus of insects, and leave for warmer climes in the autumn," said Dr. Willis. "From 2071 to 2100, nine out of the 17 species we looked at are projected to face longer migrations, particularly birds that cross the Sahara desert."

Co-author Professor Rhys Green of Cambridge University and RSPB, said, "These tiny birds make amazing journeys, pushing themselves to the limits of endurance. Anything that makes those journeys longer or more dependent on rare and vulnerable pit-stop habitats used for refueling on migration could mean the difference between life and death."

Climate change is not the only environmental concern for birds in Africa. Agricultural development, logging, invasive alien species, and unsustainable hunting and trapping are the main threats to bird species and Important Bird Areas across the African continent.

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