What happens when an animal that normally gets around quadrapedally - that is, on four limbs- is videotaped walking around on just two of them? It becomes a YouTube star, of course.
Ambam, a male western lowland gorilla living at the Port Lympne Wild Animal Park in England has become a major internet celebrity (to which I'm contributing with this very post) after videos of him getting about bipedally were posted online.
Gorillas, like most primates, have dexterous hands with an opposable thumb on their forelimbs. They normally get around on all fours by "knuckle-walking" on their bent fingers. They do have the ability to walk on two legs of course, which is something they do when they are carrying food or other objects in their front arms, or, in the case of males, when they rise up to intimidate other males or potential threats in dominance displays. But normally they don't make a habit of it because gorilla bodies are designed primarily for quadrapedal locomotion.
Why Ambam decided that he likes getting around on two legs is anyone's guess, but he seems otherwise normal and healthy. His father and sisters sometimes walked on two legs, so there is some speculation that it might be genetic predisposition. Others theorize that the bipedal behavior allows Ambam to see the human zoo visitors, who sometime toss food to him, over his enclosure wall. No matter which way you look at it, it's definitely odd behavior.
The videos were recorded as part of a research project on great ape locomotion and have sparked questions in the ongoing debate among anthropologist and primatologists on the origins of bipedalism in humans.
Western lowland gorillas are a critically endangered species.
(Photo at right is a screenshot taken from this video.)