A pair of mated male penguins in a Dutch zoo were so eager for offspring that they stole an egg from another pair of penguins.

Two male black-footed penguins (Spheniscus demersus, also known as African penguins) at DierenPark Amersfoort zoo in the Netherlands were recently found incubating a purloined egg. Their nest — holding the stolen egg — was near a nest that belonged to a male and female penguin couple, zoo representatives said in a statement.

Hatching season was already underway for the zoo's penguin community, and the males likely swiped the egg from their breeding neighbors during "an unguarded moment," according to the statement.

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Some chicks in the zoo's penguin brood have already hatched, and animal caregivers are keeping a close eye on the male couple, who are taking turns warming their ill-gotten egg, DutchNews reported. But there's a chance the couples' dreams of parenthood may soon be dashed, as the stolen egg may not have been fertilized, according to DutchNews.

Prior to the Dutch penguins' egg-snatching antics, other same-sex penguin couples have canoodled their way into hearts around the world. Roy and Silo, male chinstrap penguins (Pygoscelis antarcticus) who lived at the Central Park Zoo in New York City, were partners for six years; Skip and Ping, male king penguins (Aptenodytes patagonicus), consciously coupled at Zoo Berlin; and Sphen and Magic, young male gentoo penguins (Pygoscelis papua), found love in the Sea Life Sydney Aquarium in Australia.

All three same-sex couples fostered eggs; Silo and Roy hatched their chick in 2004, while Sphen and Magic's chick — "Baby Sphengic" — hatched on Oct. 19, 2018, the aquarium announced on Twitter. But poor Skip and Ping remain childless: Despite their attention, their unfertilized egg "burst open" on Sept. 2, German news site The Local reported.

Penguins aren't the only birds that form homosexual relationships. More than 130 birds species are known for homosexual behavior, which can include complex courtship rituals, genital contact and even nesting together for years, Live Science previously reported.

In Photos: The Emperor Penguin's Beautiful and Extreme Breeding SeasonCharming Chick Photos: Antarctica's Baby PenguinsPhotos of Flightless Birds: All 18 Penguin SpeciesOriginally published on Live Science.

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