New research led by King’s College London has highlighted the danger faced by lesser flamingos in East Africa due to rising water levels at their feeding lakes. For the first time, satellite earth observation data was used to study all 22 key flamingo feeding soda lakes in Ethiopia, Kenya, and Tanzania over two decades. The study found that rising water levels were reducing the birds’ main food source, leading to a decline in populations of phytoplankton, which the flamingos feed on. This, in turn, is likely to push the birds into new unprotected areas in search of food, posing serious consequences for the species’ future.
The study, published in Current Biology, also revealed that the degradation of the flamingos’ historic feeding and breeding sites is a serious concern. The authors warned that without coordinated conservation action across international borders, improved monitoring, and more sustainable management of land surrounding important flamingo lakes, the highly specialized species found in soda lake ecosystems, including lesser flamingos, could be lost. The research showed that as lake surface area increased, bird numbers decreased, and identified the lakes the birds might move to in the future. This has implications for conservation and ecotourism revenues in the region.
Soda lakes are some of the harshest environments on Earth, being highly saline and alkaline. Despite this, many species, including flamingos and their phytoplankton prey, have evolved to thrive in these conditions. However, the research found that rising water levels across the region’s soda lakes were diluting their normally salty and alkaline nature, leading to a decline in phytoplankton populations. This decline was linked to increases in the surface areas of the lakes, with significant losses in phytoplankton biomass observed in equatorial Kenyan lakes and northern Tanzanian lakes, which saw the largest increases in surface area.
The study also highlighted specific lakes that have experienced significant changes, such as Lake Nakuru in Kenya, historically supporting over one million birds at a time. The lake increased in surface area by 91% from 2009 to 2022, while its mean chlorophyll-a concentrations halved. Lake Natron in Tanzania, the only regular breeding site for lesser flamingos in East Africa, has experienced declining productivity alongside rising water levels in recent years. If phytoplankton biomass continues to decline at this and other nearby feeding lakes, it will no longer be a suitable breeding site for the flamingos.
In addition to researchers from King’s College London and the Natural History Museum, the team also included scientists from various institutions, including the National Museums of Kenya, the Tanzania Wildlife Research Institute, the Zoological Society of London, the University of Leicester, and the Freshwater Biological Association. The findings of the study underscore the urgent need for conservation efforts to protect the lesser flamingo population in East Africa and preserve their vital feeding and breeding sites. Without immediate action, the future of these iconic birds and the unique ecosystems they inhabit is at risk.
