Pandas aren’t only known for being picky when it comes to their diet – their peculiar reproductive behaviour is also cause for many a raised eyebrow. Strange but true: panda females are only fertile once a year, for just 24 to 72 hours at a time.
Zoo Berlin’s two pandas usually live in happy solitude in their separate habitats at the Panda Garden, but early this month they started experiencing spring fever. Female panda Meng Meng (5) began emitting high-pitched squeaking noises to attract the attention of the male, Jiao Qing (8), who responded with a bleating sound of his own. When vets confirmed heightened levels of the sex hormones progesterone and oestrogen in Meng Meng’s urine, the decision was taken to allow the two bears to meet in the flesh. On the morning of 5 April, they had their very first date – out of the public eye in order to give them plenty of peace and quiet. Zoological Director Dr Ragnar Kühne explained: “The two pandas have absolutely no experience when it comes to sex. However, Meng Meng showed obvious interest in Jiao Qing, and he seemed ready, too.” On Friday and Saturday, the two bears were left alone on seven occasions for 20 minutes at a time – under the watchful eye of two panda reproduction experts who flew in especially from China. Jiao Qing, who weighs around 110 kilos, came into very close contact with a receptive Meng Meng, but it was not possible to ascertain whether copulation actually took place.
Because giant pandas are a threatened species and every newborn is valuable, the decision was taken to artificially inseminate Meng Meng and thus increase the likelihood of pregnancy. Sperm was taken from Jiao Qing via electro-ejaculation before being inserted into Meng Meng. The two bears had to be briefly anaesthetised while these procedures were carried out. Zoo Berlin’s director, qualified veterinarian Dr Andreas Knieriem, explained that the time window for panda reproduction is very small. “I am particularly grateful to experienced breeding experts Prof. Thomas Hildebrandt and Dr Frank Göritz of the Leibniz Institute for Zoo and Wildlife Research (IZW), who helped us carry out the procedure in a timely manner on Saturday.” Prof. Hildebrandt continued: “Although artificial insemination is routine for us, we are not accustomed to performing the procedure on pandas. However, both bears coped very well with the whole affair.”
An ultrasound to determine whether Meng Meng is actually pregnant will not be carried out until June at the earliest, and a potential birth will not occur until three to six months from now. This irregular gestation period is down to the fact that fertilised egg cells lie dormant in panda mothers for an indeterminate length of time before starting to grow. A panda foetus takes 45 to 60 days to develop. Mothers give birth to one, two or three naked hamster-sized young that weigh between 80 and 200 grams – that’s around a thousandth of their mother’s weight.
Germany’s only giant pandas have lived at Zoo Berlin since summer 2017. Current estimates suggest there are just 1,860 adult pandas living in their natural habitat. The giant panda is therefore classified as “Vulnerable” on the IUCN Red List. Zoo Berlin pays an annual fee for the honour of keeping the pandas, and 100 percent of that sum is channelled into conservation work such as the breeding, protection and reintroduction into the wild of the beloved bamboo-eating bears.
