Boo, who made his grand debut on Thursday, is the first of its kind to be born at the Spain zoo in the last 20 years.
Since Boo lost his mother three months ago to lung disease, he's been raised by a zoo keeper.
Orangutans typically stay with their moms for six years.
Madrid keepers face the challenge of reintegrating Boo among Madrid's other orangutans even as the animal is fed by humans. The zoo said the process is working, as Boo readily breaks away from its 'adoptive mother' at feeding time.
The Associated Press contributed to this report.
