London Zoo has released a video of a tiny premature penguin chick that survived against all the odds.

Keepers checking the penguins’ nest boxes this breeding season found one of the eggs had been accidentally broken by its parents, and were astonished to find a little chick still alive inside.

Posting a video of the chick to Facebook, the zoo said: “She’s now doing really well and is staying in a custom-built incubation room cosying up to a cuddly toy penguin.”

The Humboldt penguin chick, named Rainbow, was rushed to the vet clinic onsite and was saved by quick-thinking keepers.

ZSL penguin keeper Suzi Hyde said: “The chick had a little way to go before she should have hatched, so it was very much touch and go – but we knew we had to get her safely out of the shell and into an incubator to give her a fighting chance.

“We were overjoyed when she started begging for food by opening her mouth wide and making tiny squawks. It was the first sign that she might just make it.”

Rainbow the penguin chick (ZSL London Zoo)

The one-month-old chick is expected to stay in the incubation room until she reaches 10 weeks old, and is being hand-fed three times a day.

Rainbow will then move into the zoo’s “penguin nursery”, which includes a shallow pool for swimming lessons, before being introduced to the other 80 penguins.

Ms Hyde said: “Rainbow’s body weight has steadily increased. She’s always eager for her next meal and makes sure we know it’s feeding time – she may be only weeks old but she’s definitely perfected her squawk already.”