it is an advantage for males who are less aggressive and show more caring, let's say "more feminine" traits, as these make better fathers. They are less likely to be killed in fights with other males, for example, and would be happier to stay at home or the nest and help more with raising the offspring.
I could be wrong on this but wouldn’t that be impossible because to reproduce the father would have to have sex with a female to have offspring, so how do you get the offspring for the father to lovingly raise if the father is gay? It seems to cancel itself out.
Sam87.