Elmer and Lima, two male Humboldt penguins at the Rosamond Gifford Zoo in Syracuse, New York, recently became proud parents to an as-yet-unnamed baby chick.

Their story started during breeding season last fall, when the two penguins coupled up, constructed a nest, and protected their territory—behavior that made their human handlers think they might make good foster parents.

As Smithsonian explains, not all breeding penguins are model expectant parents; some have a tendency to accidentally break their eggs. (In fact, Elmer survived a cracked egg during his own incubation period: The team patched it up with Elmer’s glue, which then became his namesake.) If the zookeepers think another penguin pair might be better suited to the task, they’ll move the fertilized egg to their nest and give the biological parents a fake one.

The zookeepers also used a fake egg as a test run for Elmer and Lima. “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,” zoo director Ted Fox said in a statement. “That’s how we evaluate who will be good foster parents—and Elmer and Lima were exemplary in every aspect of egg care.”

So when another penguin couple, Poquita and Vente, got pregnant in late December, Elmer and Lima were well-prepared to flex their fostering skills. They shared incubation duties, and a healthy chick hatched on January 1. Since then, the dads have diligently kept it warm and fed.

It’s not the first time Rosamond Gifford has successfully used foster parents to rear penguin chicks, but Elmer and Lima are the zoo’s first same-sex couple to get the gig. As long as they keep doing an exemplary job, they may have a chance to foster more chicks in the future.

[h/t Smithsonian]