Zoo Boise/Monte Stiles

The female baby - a type of ape called a gibbon - was born April 9.

BOISE, Idaho - The first ape ever born at Zoo Boise is being hand-raised by humans and is gaining weight, after being rejected by its mother.

The unnamed female baby -- a type of ape called a gibbon -- was born April 9 and weighed half a pound, but is now up to three-quarters of a pound, zoo director Steve Burns said. Her mother rejected her five days after she was born, Burns said.

Gibbons are the smallest member of the ape family and are part of the Species Survival Plan, in which zoos work together to try to make sure there is a viable population of specific species in captivity that could be used for reintroduction into the wild if necessary.

"They're amazing acrobats and they can swing -- even put the best gymnast to shame," Burns told the Idaho Statesman. "People really like the gibbons."

The baby gibbon is growing stronger in an incubator similar to that used for humans that Saint Alphonsus Regional Medical Center located and is renting from the Oregon Zoo in Portland.

"It's the most unusual request I've ever received at the foundation," said Linda Payne Smith, executive director of the Saint Alphonsus Foundation. "But we're very supportive of Zoo Boise, and we're very excited to be able to help."

Burns said the zoo will evaluate the baby gibbon's health after three months for possibly displaying her to the public.

"We have to take the animal's health first and foremost into concern," Burns said, noting the baby is the first ape born at the zoo. "We appreciate everyone being patient with us."

He said the baby gibbon is susceptible to human diseases.

The zoo's two adult gibbons -- the baby's mother and father -- remain on display.

Other animals at the zoo in the Species Survival Plan are Amur tigers, Amur leopards, Andean condors, ocelots (small leopard-like wild cats), red pandas, Grevy's zebra, sloth bears and snow leopards.

"Seeing animals up close and in person helps foster a greater appreciation of animals," Burns said.