A: It's evolution, baby
It’s true. Male pandas have such teensy winkies that many humans trained in the ways of sexing bears have mistaken boy pandas for girl pandas. Female pandas have a reproductive window so fleeting – just a day or two a year – that even if a male panda were to erect his little soldier, it would be unlikely to see any action. Based on these two observations, many people like to imagine that pandas are sexually inadequate, a species that would surely be extinct were it not for the supportive role played by humans.
The truth about pandas and sex is rather different and, in my considered opinion, a whole lot more interesting. When I meet someone who subscribes to the pandas-are-rubbish-at-sex school of thought, I have to ask how it is that this species has been roaming the earth – in roughly its current shape and form – for some 20 million years. This, I like to point out, is approximately 20 million years longer than Homo sapiens have been around.
Clearly, pandas do not have a problem with sex. In fact, from an evolutionary perspective they appear to be really rather good at it. So what is going on here? How did this myth get started and why is it still so widely held?
For all the evolutionary distance between pandas and humans, there are some superficial similarities. The panda is rounded like a human baby, it appears to have large, child-like eyes, with little or no tail and it sits on its bottom a lot, all characteristics that might account for the immense popular appeal of Ailuropoda melanoleuca. Lulled into an anthropomorphic mindset, it seems that many people see pandas as wannabe humans, quasi-hominids that would kill to have bigger penises, more frequent menstruation and much, much more sex.
The reality, in fact, is that those who mock pandas for being sexually incompetent are not really talking about actual pandas. They are referring to zoo pandas, a contrivance that says far more about the failure of humans than about black and white bears.
The first specimens to find themselves behind bars lived very short lives at Chengdu Zoo in the 1930s. They did not die because pandas are rubbish at surviving, but because they were given food fit for humans. The first panda to reach the West – a male called Su-Lin whose genitals are illustrated above – went on show at Brookfield Zoo in Chicago in 1936. The first panda conceived and born in captivity caused a stir, but only in 1963. London Zoo’s celebrity panda Chi-Chi braved the Cold War to hook up with a Soviet panda An-An at Moscow Zoo, but she died cubless in 1972. The Nixon pandas – male Hsing Hsing and female Ling Ling – spent the rest of the 1970s frustrating keepers at the National Zoo in Washington D.C. Artificial insemination and monitoring the reproductive hormones of females improved the captive panda birth stats a touch, but in March every year zoos the world over still go through the same pregnancy-based pantomime.
As far as we can tell, pandas do sex very differently in the wild. As pandas travel through their forested landscape, they leave frequent markings, olfactory messages that carry information on gender, age, proximity and fertility. When a female comes into season, these evolved signals attract males from far and wide. She may even be drawing many males together, letting them tussle for supremacy, then making her choice. Threesomes or more-somes are not unknown. Frequent copulation is common, some pairs having sex around 50 times in just a few hours. These are highly productive couplings too, with females rarely missing an opportunity to fall pregnant.
So the answer to the question “Why don’t pandas have more sex?” is pretty simple. Because natural selection has resulted in a different way of doing it. Of course, none of this is going to stop the silly jokes about panda sex. So in the interest of balance, I like to imagine a pair of pandas sitting together in the forests of Sichuan, cracking bamboo in a moment of postcoital bliss and cracking jokes at the expense of humans, mocking their weird, drunken mating rituals, their single-bout sex and their frequent failure to conceive.