A pair of same-sex penguins hatched their first chick at Rosamond Gifford Zoo in New York and the parents are caring for it like pros.

The two male Humboldt penguins (Spheniscus humboldti) named Elmer and Lima were given an egg to incubate because the egg's biological parents have a history of accidentally breaking them. A chick hatched from the egg on Jan. 1 and is doing just fine with its same-sex parents, who keep the newborn penguin warm and fed.

"It continues to be brooded and cared for by both Elmer and Lima, who are doing a great job," Ted Fox, the zoo's director, said in a statement.

Related: Photos of flightless birds: All 18 penguin species

Elmer and Lima paired up and built a nest for the breeding season. They didn't have any eggs of their own for obvious reasons, but they defended their territory and behaved as breeding penguins would, so zookeepers gave them a dummy egg to see whether they cared for it properly.

"Some pairs, when given a dummy egg, will sit on the nest but leave the egg to the side and not incubate it correctly, or they'll fight for who is going to sit on it when," Fox said. "That's how we evaluate who will be good foster parents — and Elmer and Lima were exemplary in every aspect of egg care." The zoo swapped the dummy egg for a fertile egg and it hatched without any issues.

This isn't the first time zoos have found success using same-sex penguins as foster parents. Both male pairs and female pairs have previously hatched chicks at a number of zoos, such as in the Central Park Zoo in New York City and the Oceanogràfic Valencia aquarium in Spain. Two male black-footed penguins (Spheniscus demersusin) in DierenPark Amersfoort zoo in the Netherlands were apparently so keen to be parents that they stole an egg from another nearby pair to raise themselves, Live Science previously reported.

RELATED CONTENT

— Photos: Belfast Zoo's new giraffe

—Here's why a new penguin colony in Antarctica is cause for concern

—Weird animal facts

Penguins of the same sex often come together as pairs. Male and female penguins share the same responsibilities when it comes to raising chicks, so there's no reason why same-sex pairs can't complete all the responsibilities of parenting, according to the Museum Studies Blog at Tufts University in Massachusetts.

Same-sex penguin pairs show that the idea of "family" is not species-specific and that in many cases, non-traditional families do a wonderful job of child-rearing, Fox said.

Originally published on Live Science.