Animals

Why Pandas Suck At Being Pandas

Pandas rely on bamboo as their main food source, but research shows that they are very bad at digesting it! Will this cause their extinction?

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The giant panda is great at looking like a giant stuffed animal, but not great at digesting bamboo, which is a problem since they spend about 14 hours a day eating the fast-growing plants. A new study from the American Society of Microbiology studied the gut bacteria of the giant panda and found they have a really hard time digesting bamboo. Of the 27.5 pounds (12.5kg) a panda eats on average per day, its stomach can only digest 17 percent, or 4.6 pounds (2.16 kg) of it.

Pandas didn't always have this problem. Evolutionary studies show that they started exclusively eating bamboo around two million years ago, but even then their gut bacteria were essentially the same as their carnivorous and omnivorous cousins. Scientists were surprised to discover that they haven't evolved some of the basic bacteria to break down the plant fibers, and yet ... that's all they have the taste for. A study published in PLOS One found a mutation on their T1R1 gene 4.2 million years ago caused them to lose their taste for meat (although they've been known to occasional nosh on a small rodent or deer fawn). This loss reinforced their herbivorous diet.

Ineffective eating habits notwithstanding, giant pandas are also have a hard time breeding, especially in captivity. Females only ovulate for a couple of days a year. If the notoriously solitary female doesn't find a male mate, they can't birth any cubs for another year. If they do, they've still got some pretty serious problems to overcome: a newborn panda is blind, tiny, 1/900th the size of its mother, and requires feeding every two hours. Yet somehow, despite all this, giant pandas has been around for millions of years.

Thanks to humans, however, their days may very well be numbered: Since we've been destroying their habitats, there are about 1,000 left in the wild and maybe 100 in zoos worldwide. Hopefully, these recent studies will enable us to help them breed (or maybe even help them digest their food better).

Learn More:
Undigested Bamboo Showing Up in Panda Poop (Discovery News)
"Even though bamboo is their main food source, giant pandas are horrible at digesting it, a new study of their gut bacteria finds."

Frequently Asked Questions about bamboo (BambooGarden.com)
"The following are questions that our customers ask on a regular basis about many bamboo related topics. Growing tips, maintaining, fertilizing, watering, growth habits, etc. The summary of questions is in the right column. Scroll down for questions (in bold) followed by answers (standard type)."

The Bamboo-Eating Giant Panda Harbors a Carnivore-Like Gut Microbiota, with Excessive Seasonal Variations (ASM.org)
"The giant panda evolved from omnivorous bears. It lives on a bamboo-dominated diet at present, but it still retains a typical carnivorous digestive system and is genetically deficient in cellulose-digesting enzymes."