Impacts of hydro climatic conditions on lesser flamingo, Phoeniconaias minor, Geoffroy populations in three Kenyan alkaline lakes

Abstract

Hydro climatic conditions are critical factor determinants of lesser flamingo ecology in the alkaline Lakes of Nakuru, Elementaita and Bogoria in Kenya. Based on lake levels, rainfall and river inflows, eight hydro climatic periods were designated and lesser flamingo numbers analyzed relative to them and other limnological conditions. Dry hydro climatic periods with reduced surface water inflows and evaporative concentration cycles were strongly correlated with challenging limnological conditions such as conductivity and pH, altered lake basin configurations and low lesser flamingo numbers. Similarly, extra wet hydro climatic conditions led to desertions as the ecosystems characteristics were altered through dilutions and limnological conditions changes resulting from excessive fresh water inflows. The shallow Lakes Nakuru and Elementaita were the most vulnerable to hydro climatic impacts and were deserted by lesser flamingos in the dry periods as the shorelines receded and largely dried out on two occasions in 1995 and 1996. Lesser flamingos shifted in large numbers to the deeper and more hydrologically stable Lake Bogoria. A similar pattern prevailed in the early relatively wet periods in 1998 and to a lesser extent in the very wet phase between the years; 2013-2015. At water depths of 70cm to 120cm in normal hydro climatic periods, lesser flamingo occupancy was highest in the Lake Nakuru and Elementaita compared to a 4m depth in lake Bogoria. As lake levels rose beyond previously unprecedented levels after 2012, lesser flamingos have increasingly moved away from the region. The study concludes that lesser flamingo populations in the alkaline lakes are intricately linked to climatic conditions and their coupled ensuing hydrological dynamics. The findings suggest that increased climatic variability associated with climate change is adversely impacting the ecology of the three alkaline lakes’ ecosystems and consequently imperiling the lesser flamingo population and its conservation in Kenya.