Taipei Zoo

On the morning of today (29th), Taipei Zoo performed a globally rare Caesarean section on the Bornean orangutan "Ke-Yi" to deliver identical twin infants. The procedure was carried out jointly by Taipei Zoo's veterinary team and the Veterinary Hospital of National Taiwan University, with support from human medical specialists in obstetrics, anesthesiology, and neonatal care, who assisted with high-risk pregnancy assessment, determining the optimal timing for surgery, and preparing for neonatal care. In approximately 3 minutes and 50 seconds, Ke-Yi successfully delivered her twins. The Caesarean delivery of orangutan twins is extraordinarily rare, with almost no precedent in international breeding records. This achievement not only marks an important milestone in Taipei Zoo's long-term commitment to the ex-situ conservation breeding of endangered species, also provides valuable experience for managing high-risk pregnancies and cross-disciplinary care in great apes.

The orangutan is listed as Critically Endangered (CR) on the IUCN Red List and is among the slowest-reproducing mammals in the wild. Female orangutans typically give birth only once every six to eight years, and more than 99% of births involve a single infant. As strictly arboreal great apes, mothers must support themselves with one arm while holding their infant tightly against their abdomen as they move through the forest canopy. As a result, in the wild, the birth of twins almost always means that both infants are unlikely to survive. Even under human care, twin births in orangutans remain exceptionally rare.

Taipei Zoo noted that although Caesarean sections in non-human primates are uncommon, there are international precedents. In recent years, institutions such as Singapore Zoo, Zoo Atlanta, and Higashiyama Zoo in Japan have handled high-risk orangutan and other primate obstetric cases through collaboration among veterinarians, animal care staff, and human specialists in obstetrics, anesthesiology, neonatology, and pediatrics. Because great apes and humans share certain similarities in pregnancy monitoring, anesthesia risks, perinatal assessment, and neonatal care, cross-disciplinary collaboration has become an important professional support model for managing high-risk pregnancies in endangered primates.

The orangutan involved in this surgery, Ke-Yi, had previously experienced a pregnancy that did not end successfully. As a result, the zoo managed this pregnancy as a high-risk case from the outset. Ultrasound examinations revealed that Ke-Yi was carrying extraordinarily rare identical twins. Because a twin pregnancy places a considerable burden on both the mother and the fetuses, allowing the pregnancy to progress to natural delivery could have increased the risks of dystocia, fetal distress, and maternal complications. After careful evaluation, the veterinary and animal care teams decided to perform a planned Caesarean section to maximize the safety of both the mother and her twins.

Faced with this high-risk delivery, where every moment mattered, Taipei Zoo activated a cross-disciplinary care team that integrated expertise in conservation breeding, animal husbandry, veterinary medicine, and human healthcare. The veterinary team also drew upon fetal ultrasound monitoring data collected in recent years. Through voluntary, non-anesthetized ultrasound training during pregnancy, they continuously monitored the twins' development and Ke-Yi's condition, providing essential information for determining the optimal timing of the surgery.

Because of Ke-Yi's previous obstetric history, together with the increasing physical burden of late pregnancy and discordant fetal growth, the team concluded that waiting until full term would further increase the risks to both the mother and the fetuses. They therefore chose to perform a Caesarean section before full term at the safest possible time. Born prematurely, the twins are very small, and their ability to regulate body temperature, maintain stable breathing, and suckle has not yet fully developed. They will require intensive care from the veterinary and animal care teams in the coming weeks.

Immediately after birth, neither infant established stable spontaneous breathing. The team promptly provided warming, respiratory support, and continuous monitoring of their vital signs. Both infants remain under intensive observation and have not yet passed the critical stage. Stabilizing their breathing, maintaining body temperature, establishing adequate nutrition, and preventing infection remain the greatest challenges ahead. The care team will continue to closely monitor both infants and do everything possible to protect these precious new lives.

Every new life is one of the most precious and fragile moments in conservation work. Faced with the many uncertainties surrounding the breeding of critically endangered species, the team will continue to support Ke-Yi's recovery with professionalism, patience, and respect for life while devoting every effort to helping her premature twins through this critical period. Taipei Zoo sincerely thanks everyone for their care and encouragement and hopes that the experience gained through this cross-disciplinary collaboration will contribute valuable experience to future great ape reproductive care and endangered species conservation.