Ambam's 21st Birthday

The Kent gorilla who has become an internet sensation after being filmed walking upright like a man is celebrating his 21st birthday today.

Ambam has been at Port Lympne wild animal park since he was 7 years old, having been born at the attraction's sister park Howletts in 1990.

But it was not until January this year, when footage of him strolling around his enclosure was posted on to the internet, that he became famous. The clip has been watched millions of times since then, and visitors have been flocking to the park to try to catch him doing it for themselves.

Gorilla keeper Phil Ridges says Ambam's family have a history of walking like this: "Ambam's father Bitam used to display the same behaviour if he had handfuls of food to carry. Ambam also has a full sister, Tamba, and a half sister at Howletts, who also sometimes stand and walk in the same way.

"All gorillas can do it to some extent but we haven't got any who do it like Ambam and he is quite a celebrity at the park."

They think Ambam may use his party trick to get a height advantage, so he can look over the wall when keepers come to feed him. Standing up also allows him to carry a lot more food, as he can use both hands, and means he does not get his hands wet when it is raining.

Ambam is the park's biggest gorilla, weighing about 220kg or 34 stone. He and the rest of his group at the park are all endangered Western lowland gorillas.

Today, to mark his 21st birthday, Ambam will be receiving some special presents. The wrapped boxes will have food inside for Ambam and his companions to find around their enclosure.