Mortalities of lesser flamingos in Kenyan Rift Valley saline lakes and the implications for sustainable management of the lakes

AbstractLesser flamingo populations in the Kenyan Rift Valley saline lakes respond to changes in phytoplankton species’ composition and densities, behavioural needs, breeding cycles and environmental conditions. The numbers of flamingos are high when the density of blue‐green algaeArthrospira fusiformis(Spirulina platensis) is high, stimulating flamingo courtship and display. The numbers decline when lake levels decline, resulting in low phytoplankton densities and a domination by toxic phytoplankton species. In Kenyan saline Rift Valley lakes, heavy metals, pesticides, algal toxins (microcystin), bacterial infection and malnutrition are plausible causes of lesser flamingo mortalities. The production of cyanotoxins by toxic phytoplankton, as a result of declining lake water levels, could be a major factor contributing to the increased mortality of lesser flamingos. Integrated management of the lakes and their catchments is required to ensure the future well‐being of the lesser flamingos.