Skipper and Ping. (Twitter)

An egg that had been adopted by a gay penguin couple “burst open” this week, but did not contain a penguin chick.

Skipper and Ping, a gay Emperor penguin couple in a Berlin zoo, had been caring for the egg since it was abandoned by a female penguin in July.

On 2 September, the egg opened, but had not been fertilised.

“Our same-sex king penguin couple has finished brooding his egg. On September 2nd the egg burst open and was unfortunately not fertilised. Surely they will get the chance to become parents again in the future,” the zoo wrote on Twitter.

Skipper and Ping were given the egg by zoo staff in July after they’d been seen to try and hatch rocks and dead fish in their desire to have a chick of their own.

The gay couple are both 10-years-old.

They took turns keeping the egg warm, putting it on their feet and then covering it with their bellies.

According to Berliner Zeitung, zoo spokesman Maximilian Jaeger said: “The two male penguins are acting like exemplary parents, taking turns to warm the egg. They kept trying to hatch fish and stones.”

Gay penguin couples raising chicks in other zoos.

It was the first time the zoo had tried to have a same-sex penguin couple care for an egg.

There have been many other gay penguin parents and couples around the world.

In July, a lesbian penguin couple at the Sea Life London aquarium became parents to a little chick during Pride month.

Also for Pride month, London Zoo’s penguin beach had a banner installed that said “some penguins are gay, get over it” to celebrate the three same-sex penguin couples that live there.

At San Francisco Zoo, a pair of male Magellanic penguins have been fostering the chicks most important to the breeding program because staff say they are “fantastic parents”.