Giant pandas live in the slow lane

Like LED lightbulbs, giant pandas are energy-saving superstars.

The bamboo-loving bears use only about 38 percent as much energy as other land mammals of similar size, researchers report in the July 10 Science. The researchers calculated daily energy use by analyzing the blood, poop and urine of five captive pandas and three wild ones. The giant bears are more like giant reptiles, the study found.

Giant pandas cut back on energy consumption by acting like couch potatoes. They move less than other bears, and when they do move, they go in slo-mo. What’s more, energy-draining organs such as the brain, liver and kidneys are relatively smaller in pandas than in other placental mammals.

The findings help explain how giant pandas can survive on a low-cal, nutrient-poor diet of hard-to-digest bamboo.

Editor’s Note: This story was updated on August 13, 2015, to clarify that panda blood and feces were sampled as well as urine.