Technically its human and sheep.
The main thing is that for all cases of homosexuality in animals they are always actually bisexual. Multiple partners at the same time also being common and they are nog picky.
With the exception of homosexuals sheep who will refuse to mate with the other gender. They are homo exclusive for life and you cannot find an exception (as far as i know)
For humans this can be anecdotally the same but because bisexuality does exist in humans and even supposedly homoexclusive people can have heterosexual experience from before they came out that i think there not comparable.
Just like hetero army guys who may pretend one of them is a women for a night, gay people can exist in loving functional hetero relationships. So even for homosexual people i would say its their main preference on top of bisexual baseline.