By Ryan Matsunaga (staff@latinospost.com) | First Posted: May 03, 2013 07:33 PM EDT

Scientists have found that two more Lemur species than previously thought hibernate during the winter. A team from Duke University has observed the pair of Lemur cousins in Madagascar, and hope that the new research reveals some clues on what exactly puts animals into hibernation.

The Crossley's dwarf lemur and Sibree's dwarf lemur were found burrowing into the rain forest floors of Madagascar, taking naps in the range of three to seven months. What scientists don't know yet is why they choose to hibernate at certain times.

"Exactly what triggers hibernation is still an open question," said lead author and a postdoctoral researcher at the Duke Lemur Center Marina Blanco in a statement.

Instead of hibernating through harsh winters like bears and squirrels, western Madagascar lemurs sleep to survive the dry season, where temperatures can top 85 degrees F and water and food becomes scarce.

Eastern dwarf lemurs on the other hand slumber through below freezing temperatures in the high altitude forests they live in.

"It's a very different environment," Blanco stated.

To survive both of these environments, the lemurs drop their bodily activity to startling levels; so much so, that they appear to be dead.

"Their bodies are cold, they are utterly still and they take a breath only once every several minutes or so," added co-author Anne Yoder, director of the Duke Lemur Center.

Scientists are planning to continue to observe the two species, in the hopes of finding out more about what makes lemur hibernation different from other animals.

The team's study is titled Underground Hibernation in a Primate and was published in the journal Scientific Reports.

Duke University released a video recapping the findings. It contains an interview with researcher Marina Blanco, footage from field research, and still images from the Duke Lemur Center.

You can watch that below.