Pygmy slow loris in Asia takes unusual downtime in winter

The pygmy slow loris truly hibernates, making it the first primate outside Madagascar found to do so, a new study says.

“Up until now there were only three species of primate known to hibernate: All lemurs in Madagascar,” says Thomas Rufof the University of Veterinary Medicine in Vienna.  But in Vietnam, new measurements of wintertime body temperature for pygmy slow lorises (Nycticebus pygmaeus) show bouts of chilly torpor lasting as long as 63 hours. A plunge in metabolic rate for more than 24 hours counts as hibernation, Ruf says.

There was talk about whether some unique conditions in Madagascar allowed the evolution of primate hibernation only there, Ruf says. But he and his colleagues dismiss that scenario December 3 in Scientific Reports.