https://www.nationalgeographic.com/science/article/101203-homosexual-birds-mercury-science
Male birds that eat mercury-contaminated food show "surprising" homosexual behavior, scientists have found.
In a recent experiment in captive white ibises, many of the males exposed to the metal chose other males as mates.
These "male-male pairs did everything that a heterosexual pair would do," said study leader Peter Frederick, a wildlife ecologist at the University of Florida in Gainesville.
"They built their nest, copulated together, stayed together on a nest for a month, even though there were no eggs—they did the whole nine yards."
(Related: "Homosexual Activity Among Animals Stirs Debate.")
Wild white ibises—among the most common birds in Florida's Everglades—are exposed daily to mercury through their diets of crustaceans and other small invertebrates.
…
What's in vaccines?
Mercury?
What a coincidence.