In today’s Academic Minute, Dr. Michelle Sauther of the University of Colorado Boulder reveals a discovery about the preferred sleeping arrangements of lemurs.
Michelle Sauther is an associate professor of anthropology at the University of Colorado Boulder. Her research seeks to better understand how both immediate and long term environmental factors interact with inter-individual variation to affect primate behavior and biology. She also heads the <http://www.colorado.edu/anthropology/lemur/overview/index.html> Lemur Biology Project, an inter-disciplinary effort to study the behavior, demography, health, and genetics of endangered lemurs at the Beza Mahafaly Special Reserve in Madagascar.
Dr. Michelle Sauther, University of Colorado, Boulder – Lemurs and Sleeping Caves
While we humans live in a stressful world that can disrupt sleep, in reality primates, including humans, spend about one third of their lives sleeping. Where we choose to sleep is a big deal. From an evolutionary perspective, one of the major factors that drives the choice of sleeping sites is safety. Studies of primates indicate that choosing a sleeping site that is inaccessible to predators is key, and in a novel study of human sleeping behavior by Spörrle and Stich (2010), they found that even humans prefer to place their beds so that they remain concealed from a bedroom’s door while allowing them to view the door from a distance.
While most social primates bed down together in trees, when we think of early humans we often envision a cave as a sleeping site. Indeed there is ample evidence in the form of ancient sleeping mats indicating that at least some ancient humans used rock shelters and caves as sleeping sites in South Africa. Our recent field research in southwestern Madagascar indicates that some groups of ring-tailed lemurs also regularly use caves as sleeping sites. Ring-tailed lemurs living in several sites along the coast of southwestern Madagascar inhabit spiny forests that provide few large trees for sleeping. These lemurs have solved this conundrum by consistently using the same caves on a daily basis, which they have been doing for at least six years.
Like ancient humans, these ring-tailed lemurs appear to seek out caves for similar reasons, to avoid predators, to keep cool during hot days and warm during cool nights, and for access to water. Cave use by other primates is very rare and our work adds to our understanding of the factors that may have driven the use of caves as shelters by our human ancestors.