Polar bears, as with all bears, are incredibly large animals. They burn up thousands of calories a day. In order to keep themselves alive they must eat high calorie meals like seals. A new study published in Science and reported on by National Geographic shows that polar bears must take in 60 percent more calories than researchers had previously believed. This is a terrible realization because climate change, and particularly its affects on diminishing sea ice means that these animals are in even more dire straits than we already believed them to be.
Because of melting sea ice, it is likely that more polar bears will soon starve, warns a new study that discovered the large carnivores need to eat 60 percent more than anyone had realized. Turns out they are high-energy beasts, burning through 12,325 calories a day—despite sitting around most of the time, according to a unique metabolic analysis of wild bears published Thursday in Science.
“Our study reveals polar bears’ utter dependence on seals,” said lead author Anthony Pagano, a wildlife biologist with the U.S. Geological Survey (USGS).
According to researchers, one of the most effective hunting techniques that the bears use is to sit in front of small seal-shaped hole and hit and grab the prey as they come up for air. Polar bears continue to burn a lot of calories, but considerably less calories than they are having to burn as melting sea ice means longer searches for hunting grounds, and less advantageous hunting environments.
The data showed the bears were active about 35 percent of the time and resting for the remainder, yet they burned through 12,325 calories a day, much of it from their body reserves. That’s about 60 percent more than previous studies had estimated. The videos revealed that four of the females weren’t able to catch a single seal. Measurements showed those animals lost 10 percent or more of their body mass.
One bear lost close to 44 pounds, including her lean muscle, in 10 days. This bear even leapt into the sea in a failed attempt to catch a seal swimming by. “She might have been desperate,” Pagano speculated.
The issue is that bears are not built for continuous walking. They lose weight very quickly, and this is balanced by their ability to gain back weight almost as quickly—but only if they are finding food. And these bears are losing their ability to find the food they need, and the ways with which to successfully catch that food.