Lake Natron in northern Tanzania is one of the harshest environments on Earth. Temperatures in the lake can rise to 140 °F (60 °C) and the alkalinity is between pH 9 and pH 10.5, almost as alkaline as ammonia. Animals who enter the water are almost certainly doomed, save certain kinds of fish that have evolved to survive in such a hostile environment.
This reminds me of Sodom and Gomorrah. The Biblical Story of Lot’s wife who was turned to a pillar of stone for looking back at Sodum when she had been instructed to flee without turning back. The idea of Devine retribution, and how these birds are somehow being punished for sins.
There are other mythical stories found in different cultures about people and animals being turned to stone, the most well known of course would be the greek myth of Medusa, the monster with the head of a woman and snaked for hair. People who looked directly at her were instantly turned to stone.
The story of Medusa also ties into the theme of punishment from Sodom. In greek mythology, Medusa and Poseidon were caught making love by the Goddess Athena in her temple. As punishment, Athena gave Medusa a hideous face and a curse to turn anybody who looks at her to stone.
These images of Lake Natron have an apocalyptic feel to them, the animals look like they have been burned and they look like something you would see on a film set rather than in reality.