Two male penguins in a Danish zoo have adopted a chick, becoming among the first gay-penguin parents in captivity.

The unnamed King penguins began performing mating rituals on each other several years ago at Odense Zoo, and zookeepers noticed both were trying to steal other couples’ eggs during brooding season. (They had even resorted to sitting on dead herring to emulate incubation.

The opportunity for them to become proud parents arose when another penguin, a female, abandoned eggs she laid with several different males. “In the lifetime monogamy of the King penguin world, this is extraordinary,” said zookeeper Nina Christensen. “Now we have an extra egg and this pair that have been standing with fishes.”

The boys parental instincts were tested on a ball first, before they were gradually moved onto the real thing. “With King penguins, they mix it between the male and female. One stands with the egg while the other goes to feed and then they shift. It was the same with this pair—they both incubated the egg,” Christensen says. “The chick hatched about a month ago and the new little family remains separated from the colony while they bond but will soon rejoin them. Penguins recognize their offspring by their distinctive cries, indistinguishable to humans, and this trio are no different.”

In 1998 Rory and Silo, two male Chinstrap penguins, became a couple at the Central Park Zoo and raised a chick, named Tango by zookeepers. Currently there are two male African penguins at the Toronto Zoo, but they’re kid-free for now.