Is apparently quite common. So much for the argument that homosexuality is unnatural. Roy and Silo, NYC's Central Park's famous gay couple, even successfully raised an adopted chick together, and I haven't heard any stories about it being poorly adjusted. But sadly, like more than 50% of straight marriages, Silo separated from Roy - and turns out to be bisexual! I think the makers of March of the Penguins missed out on a wonderful soap opera opportunity here.
Oh, and penguins can also struggle with obseity, just like humans. What a cute little microcosm!