Two male Humboldt penguins at a New York zoo who adopted an egg last year have become parents to a brand-new hatchling.

The same-sex foster couple, Elmer and Lima, are a first for the Rosamond Gifford Zoo , which is based in Syracuse, though a number of other zoos around the world have also had same-sex penguins successfully incubate eggs and raise chicks.

The Rosamond Gifford Zoo said on its website that it has had at least two breeding pairs of penguins accidentally break their fertilized eggs in the past. To improve the chances of hatching a chick, zookeepers may give an egg to a more successful pair.

Zoo Director Ted Fox said that not all penguin pairs are good at incubating eggs: It takes practice.

Elmer and Lima were given a dummy egg last year and were exemplary in every aspect of egg care, Fox said. That prompted zookeepers to give them an egg laid by another couple before Christmas.