Gibbons are great apes. There. We've said it. The purists may pooh-pooh the idea, but ours isn't a scientific definition. These so-called lesser apes may not officially rank alongside the big guns of the primate world, but in their own inimitable way they are just as charismatic and characterful as the gorillas, chimpanzees and orangutans that have had greatness thrust upon them. Many are also critically endangered, including the cao vit gibbon.