Every year, more than a million pink flamingos gather on the lakes of Africa in a shimmering ballet. But the continued rise in water levels is increasingly reducing the algae necessary for the survival of these flamboyant web-footed birds, warns a study unveiled in mid-April.
These lakes, concentrated in Kenya, Tanzania and Ethiopia, are reaching record levels for decades, in part because of increased precipitation linked to climate change. This significantly diluted the alkalinity and salinity of the water in these lakes and led to a “massive decline” of the unique algae that flamingos depend on, putting an already declining species at risk.
According to lead author Aidan Byrne, this causes birds with their distinctive pink plumage to leave their habitats and take refuge in unprotected areas in search of food.
“Surprised by the extent of the changes”
“It may be that they could move elsewhere, but they could also completely disappear from the areas where they are currently found
,” said the doctoral student from King's College London and the National Museum of Natural History in Paris.
Flamingo habitats in East Africa are protected, whereas outside, monitoring would be difficult and other threats, particularly human, could appear.
If other previous studies had already shown this phenomenon,
“we were surprised by the extent of the changes and by the threat weighing on the habitats of the pink flamingos
,” explained Mr. Byrne to AFP.
Erratic and extreme rainfall predicted for East Africa due to climate change would only worsen the problem and
"increase the threat to species in the region"
, he added. This study, published in the journal Current Biology, is the first to use satellite imagery to observe the 22 lakes that host flamingos in East Africa.
Lesser flamingos
These data were combined with climate records and bird observation data spanning more than 20 years.
The sharpest declines in algae concentrations were observed in Kenya, particularly in Nakuru, one of the most important flamingo feeder lakes in Africa. This lake grew by around 90% between 2009 and 2022, while the concentration of algae there decreased by half.
Lakes Bogoria and Elmenteita, which also attract tourists due to the sumptuous spectacle produced by the gathering of pink flamingos, have also experienced a sharp decline in both the quantities of algae and the populations of wading birds, hampering the tourist revenue of the country.
East Africa is home to three quarters of the world's lesser flamingos.
“This is an iconic species that is unique in these environments. Their disappearance would be devastating
,” underlines Mr. Byrne.
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