When there aren’t enough members of the opposite sex around, king penguins will pair off into gay couples. In zoos these couples have been given fertilised eggs and successfully hatched them and reared the chicks. Gay penguin couples will often split up and go off to find same sex partners later. The report doesn’t make it clear whether the penguins cycled between same and opposite sex partners.
Some people are trying to suggest that this somehow trumps all the other evidence of gay behaviour in hundreds of species, which is a typically huge logical jump. All it proves is that penguins are mostly bi.