Pandas Kai Kai and Jia Jia mate for the first time

River Safari's giant pandas Kai Kai and Jia Jia have officially entered their first mating season, said Wildlife Reserves Singapore (WRS) in a statement on Tuesday, April 21.

This was a cause for jubilation for River Safari's caretakers as the critically endangered bears are notoriously difficult to breed.

Keepers and vets at River Safari have employed a number of measures since last November to trigger the breeding cycle of the pandas. They have tried methods like varying the daylight hours and temperature in the panda exhibit to simulate the transition from winter to spring just like how it is in their homeland Sichuan, China.

Kai Kai and Jia Jia did respond as they showed the first signs of coming into estrus on April 5.

Both pandas were brought together for the first time in their dens on Friday, April 17, for natural mating. However, the 40-minute session was unsuccessful. WRS said it is typical for first-time breeders to encounter this as they may not know how to mate.

Dr Serena Oh, WRS Assistant Director of Veterinary Services, said: "Panda reproduction is a notoriously complex process, with females ovulating once a year, in which they are fertile for only 24 to 36 hours.

"Jia Jia's hormones started falling on Friday and we needed to move quickly to artificial insemination due to the short window when female pandas are able to conceive."

She added that WRS will continue to monitor Jia Jia's hormone levels and conduct ultrasounds to determine if she is pregnant.

The gestation period for a panda is typically five months, and one or two cubs are usually born.