A same-sex king penguin couple at the Berlin Zoo is the epitome of “exemplary” parenting after taking over parental duties of an abandoned egg, whose mother literally waddled away in mid-July for unknown reasons, reports German newspaper Berliner Zeitung.

That’s when the dynamic daddy duo Skipper and Ping stepped in.

IFLScience spoke with Vikki McCloskey, a curator at the California Academy of Science Steinhart Aquarium, who has worked with temperate penguin species for the last 15 years. She says that same-sex penguin couples are nothing new to the animal kingdom and can occur both in captivity and in the wild.

“It’s something that you see happen because in order to take care of an egg, you need a partner. You cannot incubate an egg and eat by yourself,” she said, noting same-sex penguin couples have been recorded in zoos around the world. “This is why these particular animals tend to have fairly strong pair bonds, especially if they’re successful in raising offspring.”

Raising penguin chicks is “not a one bird job” and when it comes to incubating an egg, parental responsibility requires around-the-clock care for everything from regulating temperature for proper development to offering protection from potential predators. Located in the sub-Antarctic islands, king penguins (Aptenodytes patagonicus) work together to incubate their young; if a female lays an egg, the male will place it on his feet and cover it with his belly fold until it hatches while his partner feeds at sea. Once the chick has hatched, the parents will take turns rearing their offspring and finding food at sea.

But not all penguins are cut out to be parents.

“There are a whole host of variables as to why a penguin would walk off its egg. In the wild, if your partner doesn’t come back, then you have to eventually go eat,” explained McCloskey, noting that a penguin living in captivity may abandon its egg for a social reason, age constraints, or for other reasons that might indicate the fetus has stopped developing. With any species in the animal kingdom, some parents simply do a better job at rearing offspring than others.

“We’ve had male-female couples abandon eggs and we’ve had male-male couples do a great job incubating and raising offspring,” said McCloskey. “There’s not really a rule, per se. The main imperative is to produce viable offspring.”

It’s unclear whether Skipper and Ping’s egg is fertilized, but the world will soon find out – king penguin eggs typically hatch after around 55 days.

[H/T: Berliner Zeitung]