Two male vultures that took in an abandoned egg at an Amsterdam zoo are now the proud parents of a baby bird.
The griffon vultures had been a couple for several years before a keeper at the Artis zoo placed the vulture egg, found on the ground of the aviary, in their nest, the zoo said in a Wednesday statement translated by The Associated Press.
Initially, the egg was placed in an incubator before the keeper offered it to the male birds. Once it was inside their nest, the two birds began taking turns sitting on the egg until it hatched, the zoo said.
The parents have begun feeding their adopted young with regurgitated food, the zoo added.
Same-sex behavior has been seen among other birds — scientists say more than 130 bird species are known to engage in homosexual behavior — though a same-sex pair hatching an egg is a first for the Amsterdam zoo.
In Germany, another same-sex vulture couple worked on hatching an egg together last year after it, too, was abandoned in their zoo's enclosure.
And back in 1999, two homosexual griffon vultures helped rear two babies at Israel's Jerusalem zoo, after the chicks were hatched in an incubator.
"They did a great job," the zoo's spokeswoman, Sigalit Dvir, said at the time, referring to the first chick. "They shaded him on hot days, they brought him water from a pond, they fed him, they stopped him falling from the nest."