Baby orang utan Ayaan, Ah Meng’s great-grandson, born after artificial insemination at Mandai

SINGAPORE - On paper, it was the perfect match.

Charlie, a 48-year-old resident of the Singapore Zoo, and the girl next door, Chomel, granddaughter of beloved icon Ah Meng.

The offspring of these two unrelated Sumatran orang utans would add vital diversity to the gene pool of their species, which is critically endangered. And while 29-year-old Chomel was already the mother of two, it would be Charlie’s first progeny, and would help to preserve his genetic legacy.

They were thus paired up, as recommended under a regional breeding programme for orang utans.

But when their romance failed to blossom after four years, the zoo’s animal care team turned to medical technology for help.

On March 18, following a dramatic birth by caesarean section, Mandai Wildlife Group welcomed Charlie and Chomel’s son and its first orang utan baby – and the first among its primates – conceived through assisted reproduction.

The caesarean birth, also a first for Mandai primates, was necessitated after Chomel developed placenta praevia, a condition that could complicate delivery.

The baby was named Ayaan, which means blessing in Arabic.

Mandai Wildlife Group’s deputy vice-president of veterinary healthcare and scientific programmes Heng Yirui said on May 21: “To our knowledge, this is the first documented case of an orang utan birth spanning artificial insemination, placenta praevia and a successful caesarean delivery.”

Visitors may be able to glimpse mother and son, and another baby whom Chomel is fostering, at the orang utan exhibit at the Singapore Zoo from May 21. They will be present from Thursdays to Sundays and on public holidays.

Native to Malaysia and Indonesia, orang utans are under threat from deforestation and hunting, among other things. There are three species: Bornean, Sumatran and Tapanuli.

The World Wildlife Fund estimates that there are currently around 13,800 Sumatran orang utans in the wild.

Ape-solute pairing

The zoo tries to ensure genetic diversity through regional breeding programmes with other zoos.

Ensuring that Charlie’s unique genes were preserved was critical, as a diverse collective gene pool helps keep primate populations in human care healthy and resilient, Mandai Wildlife Group’s curator of animal care (operations) Wendy Chua told The Straits Times.

“Charlie didn’t have any progeny at all, which is why he is ranked amongst the most important to breed,” she said. “If he were to pass on with no offspring, there’s nobody else left to carry his genes.”

Under the SEAZA breeding programmes coordinated regionally, the animal care team could look for a suitable partner in Singapore or abroad to match with Charlie.

In 2018, the animal care team determined that Charlie and Chomel, being genetically distant, would make a good match.

“Their offspring (would be) stronger, healthier and survive to be much better individuals,” said Ms Chua.

Since they were at the same zoo, there was no need to transport a suitable orang utan from another country.

Ms Chua said Charlie was also getting close to the upper end of his lifespan, making breeding more urgent. Orang utans can live up to 60 years under human care and between 35 and 45 years in the wild.

But when Charlie showed no interest in mating with Chomel, the animal care team decided to try artificial insemination, which had been successfully used at Mandai for giant pandas and African lions.

The team began trying from May 2022 and succeeded on the third attempt.

Charlie’s semen collection was carried out through a trained voluntary process, made possible by his comfort and trust in his caregivers.

As for Chomel, the team closely tracked and monitored her reproductive cycle to gauge the best time to insert Charlie’s semen, said Dr Heng.

He added that the success rate of artificial insemination in orang utans is thought to be under 10 per cent.

With artificial insemination in great apes not commonly performed, the team had little information and scientific research to turn to.

For assistance, Mandai also engaged a team of neonatal and obstetrics and gynaecology specialists from the human healthcare field.

Chomel had to be closely monitored, with blood and urine samples taken and undergoing several ultrasound scans, said Ms Chua.

“If she refused to be on command on one of the days, everything would just be derailed,” she said.

But Chomel turned out to be a joy to work with and did not have issues cooperating, said Dr Heng.

On July 28, 2025, Chomel was sedated and inseminated with Charlie’s semen. Three weeks later, she was confirmed to be pregnant.

“All the stars had aligned,” said Ms Chua.

Labour of love

The gestation period for orang utans is about 8½ months, and it was smooth-sailing until the keepers noticed Chomel had two episodes of notable vaginal bleeding in January, about six months into her pregnancy.

“This was cause for alarm for all of us. We were basically in a state of panic,” said Dr Heng. An ultrasound scan, however, revealed that the baby was doing well.

After further checks, the vet team found that Chomel had placenta praevia – a condition in which the placenta completely or partially covers the opening of the uterus.

This could have complications for a natural birth, especially for the mother, said Dr Heng.

“If the animal were to go through natural birth, the baby would tear through the placenta and result in severe bleeding (for the mother),” he added, noting that the condition in orang utans is not well documented.

Chomel could bleed to death.

Mandai opted to deliver the baby by caesarean section. It set the surgery for March 18, about eight months into Chomel’s pregnancy.

The big day

Following weeks of extensive discussions and tabletop exercises during preparations, Chomel was placed under general anaesthesia at her den and then transported to the zoo hospital on the morning of March 18.

Blood had been collected from her cousin, who is also called Ah Meng, in case she haemorrhaged and needed a transplant. A team of neonatal and obstetrics and gynaecology specialists was also on site to give advice.

A 10cm incision was made, and the 1.6kg baby was delivered successfully at 9.45am. The whole procedure took about 20 minutes.

The operating theatre was silent when the baby was lifted from the womb.

Instead of making a healthy wail and being of pinkish hue, the infant, slightly larger than two hands, was silent and had a blue tinge. The tension in the room was palpable.

A healthy newborn orang utan should be strongly gripping and clinging almost immediately, which is instinctive for arboreal species whose survival depends on holding on to mum, said Ms Chua.

Ayaan had a low heart rate, with no vocalisation and a weak response to touch.

Dr Heng said: “If the baby didn’t breathe or make any noise by three minutes, we would have declared him dead.”

But the baby began showing signs of life, with his heart rate and colour increasing by the minute. The team waited. At the seventh minute, when he took his first breath, the team finally let go of theirs.

“It’s the longest seven minutes I’ve ever faced,” said Ms Chua.

In the meantime, Chomel was stitched up and transferred back to her den. The baby was placed in an incubator and returned to his mother at 1pm.

“There was an immense sense of relief when Ayaan took his first breath, and even more so when Chomel woke up from anaesthesia and took him into her embrace,” said Dr Heng.

She began nursing Ayaan within 24 hours of the procedure, said Mandai.

For a while, Chomel showed signs of discomfort and lacked appetite – until she was tempted by durians, said the team. She has now fully recovered, and both mother and son are doing well, said Mandai. On top of caring for Ayaan, Chomel is also fostering a baby belonging to another orang utan.

Dr Heng said his team is looking to publish this successful birth in scientific journals to help zoos dealing with similar cases in great apes under managed care.

“As people on the front line having to deal with a situation like this, there was really not much information for us to rely upon, for us to be able to replicate the successes of others,” he said.

“Having to navigate this ourselves now and having a success on our belts put us in a position to then share whatever we have done with the rest of the world, with the zoo community and with primatologists as well.”