Giant pandas have been puzzling scientists for decades. Although they have a stomach that is perfectly fit for digesting meat they stubbornly rely on bamboo sticks to fulfill their daily energy dose.
A new study revealed that the mystery behind such weird behavior may be linked to pandas’ metabolism and general lifestyle. The cute beasts originating in the mountains of central China can survive on bamboo alone because they are… lazy. As lazy as the infamous three-toed sloth which watches its every move, or doesn’t move at all just to preserve its energy levels.
So, less physical activity combined with low activity in their thyroid gland is the perfect answer to how pandas can survive while being herbivores. They are the only herbivore species out of eight bear species we currently have on Earth.
Scientists were puzzled by pandas’ diet choices because their ancestors were full-fledged carnivores. So, they inherited from those ancestors a digestive system that can easily handle meat although the pandas continue to chew on their favorite food which accounts for 99 percent of what they eat. But because bamboos are hard to digest and have a low-nutrient content, the bears must eat lots of them during a day.
During their research, scientists monitored three giant pandas living in a natural reserve in the Shaanxi province in China and five giant pandas held captive in the nation’s capital.
Study authors learned that pandas spend only 38 percent of the energy their similar-sized peers do on a daily basis. The secret behind this achievement is their low metabolism. Their bodies release thyroid hormones at a remarkable low pace. The team suggests that that may have something to do with a mutation in a gene dubbed DUOX2. Thyroid hormones can adjust the animal’s metabolism including energy levels.
Fuwen Wei, lead author of the study and biologist at the Institute of Zoology of Chinese Academy of Sciences in Beijing, explained that giant pandas switched gradually to a slower metabolism.
The panda study was published Thursday in the journal Science.
Researchers wrote in their paper that the panda’s internal organs including kidneys, liver and brain are smaller than those of other bear species.
“These reduced organ sizes likely contribute to their low energy demands,”
Additionally the team also found that giant pandas that live in the wild are incredibly slow movers. They only move about 20 meters or 65 feet per hour and they routinely sleep more than a half of a day. Their thick fur shields them from heat loss, which would have been a real problem taking into account their low metabolism.
Image Source: The Guardian