The answer is orangutans.
In 2006, NHNZ series producer Judith Curran began work on Orangutan Island, a 13-part series which followed the fortunes of 35 orphaned orangutans in the rainforests of Borneo.
After four years of "forest school" at the Nyaru Menteng Rescue and Rehabilitation Centre, the animals were filmed adapting to life on a 40ha island sanctuary .
"It's like Coronation St and Lord of the Flies but on Orangutan Island.
The group of young ones in our story are the equivalent of human 10 to 12-year-old kids, so there's triumphs and tragedy as they grow up," Ms Curran said.
Footage of the animals forming relationships and facing threats such as snakes and illness were interspersed with archival footage of their "rescues" as infants.
Orangutan Island was launched in the United States on the Discovery Network's Animal Planet in November last year.
The series created an "explosion of interest" in the endangered species and donations to the organisation running the animal rehabilitation programme, the Borneo Orangutan Survival Foundation, "increased dramatically", Ms Curran said.
Orangutan Outreach director Richard Zimmerman said donations to the US branch of the organisation reached unprecedented levels after the series was broadcast.
"We essentially owe all our success to Orangutan Island. It allowed us to start bringing in donations quickly and steadily. By the end of the first season, we had generated a ton of adoptions - about 600 - and a significant number of donations.
"When the series ended, our numbers slipped immediately. Reruns gave us a nice bump but we have never gone back up to earlier levels.
"We are eagerly awaiting the second season and the success it will surely bring," Mr Zimmerman said.
Because orangutans have the second longest dependency period - apart from humans - they have often not learnt necessary survival skills if separated from their mothers before the age of 8.
Rehabilitation project manager Lone Droscher-Nielsen is trying to find protected habitat for nearly 1000 orphans.
The programme is believed to be largest primate rescue organisation in world.
"What's so incredible is they aresolitary by nature and don't live in structured societies like chimpsand gorillas.
"But, in these circumstances, they areforming amazing societies and transferring maternal bonds to eachother.
"It's profound and reflects the way ourown society is organised. There are eerie similarities withhumans," Ms Curran said.
Ms Curran said hiring Queenstown-basedcameraman Alex Hubert was a "stroke of genius".
"Alex has never done wildlife andtakes an unconventional approach.
"He becomes immersed in the groupand is completely accepted into their slightly artificial society. He films in close without beingobtrusive."
She described producing the series as"the pinnacle" of her career.
The second series of Orangutan Islandwill premiere on Animal Planet in the US later this year.
The first series will screen in NewZealand from September 10.
