Lesser flamingos breed on highly caustic East African soda lakes that provide protection from most predators, but can cause severe chemical burns to chicks whose legs become encrusted with soda crystals during their first weeks of life.
Lesser flamingo chicks face a uniquely caustic welfare challenge in their first weeks of life. Born on the alkaline flats of Lake Natron, they must march to freshwater sources before their leg feathers grow to protect them. During this journey, caustic soda crystallizes on their unprotected legs, forming heavy anklets that can exceed the body weight of a small chick. Affected chicks slow down, fall behind, and eventually cannot walk at all. Without intervention they die of thirst, predation, or the burns caused by the crystals themselves. Conservation workers who chip away these anklets and release chicks provide a direct welfare intervention — but the scale of the problem during bad years can overwhelm volunteer capacity. The caustic environment that makes Lake Natron safe from most predators is simultaneously a welfare hazard for the most vulnerable life stage of the flamingos that depend on it.