African migratory birds threatened by hot, dry weather
Africa’s migratory birds are threatened by changing weather patterns in the center and east of the continent that have depleted natural water systems and caused a devastating drought.
The warmer and drier conditions resulting from climate change are making it difficult for traveling species to lose their water sources and breeding grounds, and many are now threatened or forced to completely change their migration patterns by settling in cooler northern areas.
About 10% of Africa’s more than 2,000 bird species, including dozens of migratory birds, are endangered, with 28 species – such as the Madagascar’s white-tailed eagle, the Taita falcon and gray vultures – classified as ‘critically endangered’. More than a third of them are particularly vulnerable to climate change and extreme weather, according to an analysis by environmental group BirdLife International.
“Birds are affected by climate change just like any other species,” said BirdLife policy coordinator Ken Mwathe. “Migratory birds are more affected than other groups of birds because they have to keep moving,” making it more likely that a location they rely on during their journey has been compromised in some way.
The African-Eurasian flight path, the flight path for birds traveling south through the Mediterranean and the Sahara in winter, is home to more than 2,600 migratory bird sites. An estimated 87% of African sites are at risk from climate change, a higher proportion than in Europe or Asia, according to a study by the United Nations environmental organization and conservation group Wetlands International.
Africa is more vulnerable to climate change because it is less able to adapt, said Evans Mukolwe, a retired meteorologist and scientific director at the World Meteorological Organization.
“Poverty, biodiversity decline, extreme weather, lack of capital and access to new technologies” are making it harder for the continent to protect habitats for wild species, Mukolwe said.
Higher temperatures due to human-induced climate change and less rainfall are shrinking key wetland areas and water resources that birds rely on during migrations.
“Lake Chad is an example,” Mwathe said. “Before birds cross the Sahara, they stop at Lake Chad and then move to the northern or southern hemisphere. But Lake Chad has gotten smaller over the years,” jeopardizing its ability to support birds, he said.
Dehydrated birds mean harder travel, impacting their ability to breed, says Paul Matiku, executive director of Nature Kenya.
Flamingos, for example, which normally breed in Lake Natron in Tanzania, probably won’t be able to “if the migration journey is too rough,” Matiku said.
He added that “no water in those wetlands means no reproduction will take place,” because flamingos need water to create mud nests that keep their eggs away from the intense heat of dry soil.
Non-migratory birds are also having a hard time with the changing climate. African ospreys, which are found all over sub-Saharan Africa, are now being forced to travel farther in search of food. The number of South African Cape Rockjumpers and Protea canaries is declining sharply.
Bird species living in the hottest and driest areas, such as in the Kalahari Desert that spans Botswana, Namibia and South Africa, are approaching their “physiological limits,” according to the latest assessment by the UN climate expert panel. It added that birds are less able to find food and lose body mass, causing widespread deaths for those living in extreme heat.
“Forest habitats are getting hotter due to climate change and … dry terrestrial habitats are getting drier and savanna birds have no food because grass never has seeds, flowers never fruits, and insects never appear the way they do when it rains,” Matiku said.
Other threats, such as illegal wildlife trade, agriculture, urban growth and pollution, are also hampering bird populations such as African ospreys and vultures, he said.
Better land management projects that help restore degraded wetlands and forests and protect areas from infrastructure, poaching or logging will help conserve the most vulnerable species, the UN Environment Agency said.
Birds and other species would benefit from concerted efforts to improve access to water and food security, especially as sea level rise and extreme weather events continue, said Amos Makarau, the UN weather agency’s regional director for Africa.
Scientists say cutting emissions of planet-warming gases, especially in high-emission countries, could also limit future weather-related disasters.
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