Griffon vultures can form gay couples and take care of eggs
As seen in some penguin couples, homosexuality within the bird species is much more common, contrary to popular belief. For example, a simple search on the internet about gay bird couples will show many examples of homosexual birds taking care both for each other and for eggs in zoos or their natural habitats.
In 2017, for example, a couple of gay griffon vultures were given an abandoned egg. Their parental instincts kicked in, so they took care of the egg together. Once the egg hatched, without any hesitation whatsoever, the couple raised their newly found chick as if it was their own.