Not so long ago, the cute and curious ring-tailed lemurs of southwestern Madagascar had scientists stumped.
Each morning, for about a week, the scientists would arrive in a forest they knew to be populated by ring-tailed lemurs to find the small primates seeming to materialize out of nowhere.
Then the scientists would watch as the lemurs went about their business -- wrapping their arms and tails around each other to form a “lemur ball” for warmth, and then going out to eat baby birds, insects or whatever they could find.
It was all very cute and charming, but what the scientists wanted to know was where did these guys actually sleep?
Ring-tailed lemurs usually spend the night in the tall canopy of trees, but these lemurs were living in an unfriendly forest where the trees were lined with spines, making sleeping in them very uncomfortable, if not impossible.
The scientists arrived earlier and earlier to see where the lemurs were sleeping and finally arrived early enough to see groups of lemurs emerging from ... limestone caves.
“We didn’t even know the caves were there,” said Michelle Sauther, a professor of anthropology at the University of Colorado at Boulder who has been studying ring-tailed lemurs for more than 20 years.
Lemurs one, scientists zero.
Sauther had spent most of her time studying lemurs in what is called “the gallery forests” -- a sort of lemur paradise with big tall trees to sleep in, running rivers to drink from, and ample food scattered around the forest floor.
But these lemurs had made their home in the less hospitable “spiny forest,” where food and water are less easy to come by and the trees are not so great for sleeping.
“Lemurs are often considered the dummies of the primate world,” said Sauther, “but our study shows they are able to deal with an incredible range of environments to figure out how to exist in amazingly challenging habitats.”
In the last seven years, the scientists have observed the same group of lemurs returning to the same cave night after night. “They have a real sense of place,” Sauther said.
She also mentioned that the lemurs are very careful before entering the cave -- almost like it is a secret clubhouse.
“Before they go in they are very careful -- they look around like they don’t want anyone to see them,” Sauther said.
Sauther’s study was published in the November issue of Madagascar Conservation and Development.
One man’s limestone cave is a secret lemur clubhouse to me. Follow me on Twitter for more stories like this.