yes, as far as i'm aware, all species they have researched have found homosexuality. Male penguins that raised a baby together is a good example. (Penguins mate for life). Also flamingos have shown the highest numbers of bisexuals. Fact is animals don't have homophobia, only humans do. Homosexuality is natural and just as vital to human survival as hetrosexuals.
Homosexuality doesn't keep earth repopulated so in an apocalypse they wouldn't be much use in that area