The Toronto Zoo family has grown a little larger with the birth of two red panda cubs.
On Monday, the zoo announced the cubs were born last week in a cozy nest box in the red panda house created by their mom Sakura.
The zoo says Sakura arrived back in January in a state of “retirement” from the AZA Red Panda Species Survival Plan. Prior to her arrival, she spent the first few weeks of the breeding season with her former mate, Arun and as a result, became pregnant when she was nearly 11 years old.
“It seems they shared a passionate goodbye!” the zoo said in a social media post.
At first, staff believed Sakura’s fertility was declining following an unsuccessful breeding season last year. However, after being housemates with Arun, staff collected fecal samples in February and the zoo’s reproductive science team decided to perform a hormone analysis.
In March, staff discovered Sakura had elevated fecal progesterone levels, indicating pregnancy was possible. According to staff, predicting pregnancy in red pandas is challenging to determine.
“After a successful breeding, a female’s body acts like she is pregnant (including physical, hormonal, and behavioural changes) whether or not she successfully conceived,” the zoo explained.
“The difficulties in diagnosing pregnancy vs. pseudopregnancy are compounded by delayed implantation, where a fertilized egg pauses before implanting into the uterus, remaining dormant until optimal body conditions are reached. The only way to confirm pregnancy is by ultrasound, which is generally not effective until close to the due date,” the zoo continued.
According to the zoo, evidence shows there is a high percentage of early pregnancy loss in red pandas compared to other species. About 40 per cent of pregnancies are lost prior to birth, based on a recent ten-year study by the Cincinnati Zoo.
In addition, other studies have shown that as few as 40 per cent of cubs also reach their first birthday.
“These low survival rates have a significant impact on the growth of the red panda population under human care. Wild red panda cubs face similar mortality rates due to their vulnerable state at birth and ongoing threat of illegal hunting and habitat loss,” the zoo said.
In Sakura’s case, she was trained to participate in voluntary ultrasound sessions and was prepared for ongoing follow-up appointments.
On June 4, the wildcare team found the first conclusive observation of fetal development. Later that same week, the veterinary team confirmed bone development and fetal heartbeats revealing two cubs.
This comes following weeks of observing Sakura who recently spent more time in her nest boxes, a preliminary sign of birth preparation. The cubs were born on the afternoon of June 13, the first cub was born at 1:15 p.m. and the second came 15 minutes later.
Currently, wildcare staff is giving Sakura and her new kids time to bond, which is why they will not be visible in the red panda habitat for guests.
In April 2015, the conservation status of red pandas was elevated to Endangered by the International Union for Conservation and Nature (IUCN).
