They can leap playful somersaults or maul a human to death.
Meet the chimpanzee, man's closest relative.
Today, Philip, a powerful male, plays tricks to earn a juicy passion fruit. But last year he was among 31 chimps from the Tacugama sanctuary in Sierra Leone that fatally mauled one man and attacked four others after escaping.
Most of the runaways, including Bruno, the group's aggressive leader, were recaptured in the mist-shrouded forests around Freetown, Sierra Leone's war-scarred capital.
Sanctuary director Bala Amarasekaran, who started adopting orphaned chimps 20 years ago after rescuing Bruno as a baby, said the attack was a tragic reminder that chimps are dangerous animals that belong in the wild.
"This problem was created by humans. Every single resident at Tacugama was once living in the wild peacefully with their own kind," said Amarasekaran, whose reserve houses more than 80 apes. "It was humans who killed their families."
For every chimp saved, he estimates that 10 are killed by hunters who then sell the meat.
Sierra Leone, a country in West Africa, was home to more than 30,000 chimpanzees in the early 1970s. Fewer than 3,000 are thought to remain, as man has hunted the animals and chopped down almost all of the jungles.
With chimp populations in steep decline in much of Africa, many people adopt cute baby apes whose parents have been killed, not thinking about the danger they pose.
Chimps are fierce and territorial, and their bodies are five times stronger than a man's. Wild chimps will not attack a taller human, but domesticated chimps quickly realize they have a physical advantage.
Orphaned chimps have been scarred by years of abuse. For most, their first experience with people was the slaughter of their families. No wonder they sometimes react violently to humans.
Of the four subspecies of chimp, western chimpanzees -- found in the jungles of Sierra Leone, Guinea, Ivory Coast and Liberia -- are the second most endangered, with about 39,000 in existence.
Stiffer Penalties Now in Place
Sierra Leone, one of the world's least-developed countries, has not made ecology a priority. However, penalties for capturing and killing chimps have been increased. Offenders now face a $1,000 fine or jail time.
Many of the rescued chimps at the Tacugama sanctuary came from well-meaning people who wanted to give them homes. Amarasekaran warns against such behavior. His most pampered resident arrived one day in the official car of then-president Ahmad Tejan Kabbah, who persuaded his son to part with his pet ape.
Amarasekaran hopes one day to free all the sanctuary's apes into the wild.
-- Daniel Flynn, Reuters