The giant panda is a conundrum for scientists. We all know they eat a ton of bamboo. And, they have the digestive system of a meat eater despite munching on bamboo all day. The average panda knocks down 20 to 30 pounds of bamboo every day. Some eat as much as 50 pounds.
Why? Scientists believe the pandas low energy demand is directly related.
Scientists from the Chinese Academy of Sciences, Beijing Zoo and the University of Aberdeen studied giant pandas and revealed a new feature. Pandas are cool.
In a study published in the journal Science, the team of scientists measured the metabolic rates of pandas living in zoos and the wild.
They found the metabolism rates in pandas were incredibly low. A 200-pound panda uses just half the energy of a 200-pound human. Whew, I’m glad mine isn’t that bad.
Why is the metabolism so low? Several factors come into play.
You know how pandas spend large portions of the day eating? Well, that means they’re not moving.
“Using GPS loggers attached to pandas we discovered that they rest for more than half of the day and on average, only travelled at 20 metres an hour,” said John Speakman, co-first author of the study.
Giant pandas live a solitary life at elevations between 5,000 and 10,000 feet. The typical adult has a defined territory where it spends life roaming bamboo forests in several mountain ranges located in central China.
Image credit: Yonggang Nie
Pandas also have a thyroid problem. Speakman added, “we found that their low metabolism is correlated with very low levels of their thyroid hormones, which was linked to a genetic mutation in the thyroid hormone synthesis pathway that is unique to the panda.”
The thyroid hormone levels in pandas were just a fraction of what is typically seen in active bears. It was comparable to a black bear’s if it was hibernating.
Now we get to the ‘cool’ part
Keeping warm with a low metabolism rate isn’t easy. Pandas’ trademark thick black and white fur help insulate what body heat they do have, but scientists found their surface temperature was cool.
It was much cooler than what you see in other black and white animals such as zebras.
Image credit: Yonggang Nie
The team of scientists also noted smaller organs including brain, liver and kidney compared to other bears.
What does the study mean? It shows that being lazy and having a slow metabolism means a panda can chew on bamboo all day, despite having the gut of a carnivore. Nope, this doesn’t mean I can kick back with some bamboo and Netflix. We can think our big energy using brains for making sure we have some semblance of a varied diet.
Professor Fuwen Wei expressed his excitement about conducting the study. “It is my long-time dream to accomplish this fascinating study to understand how low the giant panda metabolism would be, and why the giant pandas can survive on their specialised and low-quality bamboo diet. Finally we have done it!”