Siamang Gibbon On Birth Control Surprises San Diego Zoo With Baby

SAN DIEGO, CA – A new baby siamang gibbon ape came as quite a surprise at the San Diego Zoo. A 37-year-old primate recently welcomed her seventh baby – despite being on birth control.

The siamang, named Eloise, gave birth in the zoo's exhibit on Nov. 12 while volunteers and guests watched the surprise arrival. The new arrival is the zoo's first siamang baby in more than 12 years.

"It was amazing to see Eloise give birth this week, because she showed no outward signs of being pregnant," said Jill Andrews, animal care manager at the San Diego Zoo.

Eloise and a 35-year-old male siamang, named Unkie, had conceived six babies in the past as part of the zoo's breeding program. Given that their genes had already been passed on several times, the zoo had limited the pair's fertility with chemical birth control for a number of years prior to the surprise birth.

"We're not certain why birth control didn't work in this case, but as with humans, it is not uncommon for contraceptive failure to happen from time to time," Andrews said. "Still, we are overjoyed — because any birth of an endangered species is a reason to celebrate."

Siamangs are an endangered species of gibbon, a lesser ape found in the tropical forests of Malaysia and Indonesia. They are classified as endangered by the International Union for Conservation of Nature due to habitat loss brought on by logging and agriculture as well as illegal pet trading, according to the zoo.

The baby is doing well, zoo officials said. The zoo's animal care staff will determine the baby's gender in the coming months when they have a chance to give the infant a full examination.

Zoo guests can visit mom, dad and their newest addition along the zoo's Orangutan Trail.

Photo taken on Friday, Nov. 16, 2018 by Tammy Spratt, San Diego Zoo Global