Newborn white-cheeked gibbon at Brookfield Zoo

As Indah, a white-cheeked gibbon, quickly swung from tree branch to vine, a tiny head hidden near her abdomen would become visible for only brief moments.

Indah's newborn son held on tightly Wednesday morning as Indah surveyed their indoor exhibit in Tropic World at Brookfield Zoo and reached out to grab a grape tossed to her by Nava Greenblatt, a senior keeper with Asian primates.

One-month-old Reo (pronounced Ray-O) was born Nov. 13 at the zoo.

Sondra Katzen, a zoo spokeswoman, said Indah, 19, had two miscarriages and two stillbirths in the past. To monitor her most recent pregnancy Dr. Susan Murrey, an obstetrician/gynecologist at Adventist Hinsdale Hospital, performed an ultrasound on Indah in September and found everything to be normal.

Greenblatt said Reo's father Benny, 22, doesn't interact very much with the infant right now, but he is placed in the same exhibit as Reo and Indah.

"(Benny's) relationship with the infant will change as the infant gets older," Greenblatt said. "He will play with him."

Greenblatt said that keepers saw Benny touch Reo for the first time on Tuesday.

Other areas where gibbons see change as they get older has to do with the color of their coat. When gibbons are born their fur is blonde and becomes slightly darker when they reach about 6 months old. When gibbons are around a year old their coat is mostly black with light colored cheeks.

Once gibbons reach sexual maturity at 6 to 7 years old the female's coat will change back to blonde and males will remain black with white highlights.

Gibbon's natural habitat includes Laos, Vietnam and China and Greenblatt said they are more endangered than the other species of gibbons.

"There are so few gibbons in zoos they are all important to the population," Greenblatt said.

Jay Petersen, the mammal curator at Brookfield Zoo, said gibbons first came to the United States from Vietnam during the war in the '60s. Since then, breeding programs and zoos have kept detailed histories about their gibbons so the population doesn't grow too fast or slow and so related gibbons don't mate.

Reo, Indah and Benny can be seen from 10 a.m. to 2:30 p.m. in the Asia section of Tropic World.