Lake Nakuru is so caustic that no fish can live in it — yet its shallows once drew more than a million flamingos. The ornithologist Roger Tory Peterson called the gathering the greatest bird spectacle on earth. Sitting at 1,754 metres on the floor of Kenya's Great Rift Valley, this is a shallow soda lake with no outflow, its water turned strongly alkaline by minerals that have no way to drain away. That chemistry feeds a bloom of blue-green spirulina algae, the near-exclusive food of the lesser flamingo, and when the birds massed to feed they stained the entire shoreline pink. Protected since 1961, the park was fenced in 1987 as one of Kenya's first rhino sanctuaries; today both black and white rhino graze here, alongside reintroduced Rothschild's giraffe. In 2011 Nakuru joined Bogoria and Elementaita as the UNESCO-listed Kenya Lake System of the Great Rift Valley.
The flamingos are no longer a sure thing. Since about 2010 the lake has swollen — from roughly 40 to nearly 70 square kilometres — and the fresher, deeper water has thinned the algae the birds depend on, scattering the great flocks to Bogoria, Elementaita and Natron. Floods in 2020 and 2024 drowned lakeside woodland and swallowed the park's old main gate, leaving a rim of bleached, dead acacias standing in the shallows. What remains is one of East Africa's richest wildlife stages: more than 450 bird species, rafts of great white pelicans, lions that sometimes rest in the yellow-barked fever trees, buffalo and waterbuck by the shore. From the Baboon Cliffs on the western escarpment the whole basin opens below — the pale lake, the drowned trees, the euphorbia forest climbing the slopes. When rain and algae align the flamingos still gather in pink ribbons; the difference now is that nobody can promise them.