(CNN)Cut off from the mainland, Ngamba Island is a world away from the rest of Uganda. Perched in the waters of Lake Victoria, this lush outcrop, a short boat journey from Entebbe, is an idyl and a haven for mankind's closest relation.
Ngamba, the island of the apes
Chimpanzees face exploitation by humans, whether through deforestation or traffickers, but Ngamba's semi-tropical rainforest has become a happy stomping ground for the primate. Overseen by the Chimpanzee Trust, the Ngamba Island Chimpanzee Sanctuary's approach helps the apes stay fed and watered, but in the daytime they're free to roam and claim the island as their own.
Ngamba's chimp population has endured difficult previous lives: orphaned, kept as pets, some used in circuses. But together they've forged a society on Ngamba, one growing in depth and complexity across nearly 20 years. The island has become the home some humans have deprived them of.
Ngamba's 49 chimpanzees are part of an estimated 200,000 left in Africa -- a fifth of the population that existed a century ago, says the trust. "Chimpanzee are classified (as an) endangered species ... there's a real need to protect the population," says executive director Lilly Ajarova.
Studying the transition from captivity back into the wild tells us much about their future, and a little about ourselves.
"Each chimpanzee here has its own unique story," says Joshua Rukundo, conservation programs director. "It's interesting (getting) to know these individuals and their stories."
Aykuru was rescued by a police officer from the arms of her dead mother, and is the best of the group at using tools. Cho came to Ngamba with her baby. Sunday is 33 years old and has been a resident since 1998, although in 1999 he nearly escaped aboard a boat commandeered from a group of curious fishermen.
The Chimpanzee Trust constantly gathers information on the island's residents, working alongside the Max Planck Institute in Germany for the past 11 years. Chimps can live up to 60 years, so it's a long-term research project.
"Our whole team is interested in the evolution of cognition," says Johanna Eckert, a member of the department of evolutionary anthropology at the institute. "We try to find out how chimps think, what kind of problems they can solve in their daily lives, and on the other hand we try to find out something about our thinking and how it evolved."
Chimpanzees normally live in highly stratified groups. Newly introduced males in particular are treated with a healthy dose of skepticism. It can take up to two years for a new chimp to be fully accepted, depending on whether the group thinks the newcomer might have designs on becoming the alpha.
However, "they have all been able to gel into one community," says Rukundo. Integration has been "one of the biggest successes" of the project, adds Ajarova.
It's not a typical sanctuary, but Ngamba seems to have found a winning formula. Humans have been responsible for much of the suffering these chimpanzees have been subjected to, but the island's dedicated staff are redressing imbalance and injustice.
"They play a vital role in the ecosystem we live in," says Ajarova. "It's really important that the public out there gets to appreciate that the chimpanzees have their own place on this planet."