Poor pandas. While the iconic bear species of China is no longer endangered, discussions about their reproductive challenges continue to intrigue people on the internet. But for scientists and wildlife conservationists, pandas’ poor sex lives are no laughing matter. In fact, the survivability of an entire species may hinge on it.

A Plethora of Problems

Despite decades of efforts by conservationists to aid their breeding in captivity, giant pandas still struggle significantly with natural mating. To be fair, it’s extremely challenging to mate as a panda. Females are only in the mood during one very brief, 40-hour fertility window each year. If they miss that mark, panda keepers have to monitor the potential mom until the next spring before she can attempt to have a baby.

The timing is tricky, but so are the personalities of the pandas. These bears have evolved to be very solitary creatures. In captivity, zookeepers have to place them in separate pens. Despite their lovable appearance, giant pandas are very territorial and will kill each other if kept close to each other for too long.

Not only that, but the males are bad at sex. Really bad. They often are unable to mount females properly, which is extremely frustrating due to the very short fertility window. The only exception is Pan Pan, a panda hunk that sired dozens of cubs until he passed away in 2016 at the venerable old age of 31 (the oldest panda in the world to this day). Of the 600 or so pandas living in zoos and research centers worldwide, more than 130 of them are descendants of Pan Pan. The rest of the males… well, not so prodigious.

As if panda mating wasn’t complicated enough, a new study has found another potential cause for the panda’s lackluster libido. Recent findings from Beijing Normal University suggest that the microbiomes of these bears may also be to blame for poor reproductive performance.

A Microbial Influence on Panda Mating?

Researchers have turned their focus to the panda’s gut, examining whether its microbiota — the community of microorganisms residing in the digestive system — could affect their sexual drive. In humans, gut microbes can impact both physical and mental health. So, the researchers were curious whether pandas’ gut bacteria might be influencing their reproductive behavior.

During the study, scientists analyzed fecal samples from 20 male giant pandas and saw noticeable differences between the microbiomes of the more sexually active pandas and their less interested counterparts. Those deemed successful in mating exhibited higher levels of Clostridium bacteria.

The Beijing researchers believe that a microbiome imbalance may be a factor in panda reproductive success. This discovery could pave the way for dietary adjustments in captivity.

A panda’s daily diet consists almost entirely of the leaves, stems, and shoots of bamboo. Bamboo provides very little nutritional value so pandas must eat dozens of kilograms every day to meet their energy needs.

One possible solution would be to more closely match the diets of captive bears with those of their wild counterparts. For instance, bamboo shoots in particular may foster higher Clostridium levels. The different types of bamboo should also be rotated at different times of the year.

This holistic approach to conservation, considering both the physical and microbial health of animals, may lead to more effective strategies in preserving not only pandas but potentially other species facing similar reproductive challenges.

“Our study provides a theoretical and practical basis for further studying the behavioral degradation mechanisms of giant pandas and other endangered mammal species,” the researchers concluded.

The findings were reported in the journal Ecology And Evolution.