these researchers hardly ever spot madame berthe's mouse lemur the world's smallest primate. >> madams mouse lemur can be found here, along with the grey mouse lemur, but it can only be found here in this forest. its entire global presence is within these few square kilometers. that means madame berthe's mouse lemur is incredibly hard hit when hundreds of hectares of forest are cleared here. that is a huge part of its remaining natural habitat. of all the species of lemur, >> madame berthe's mouse lemur is most at risk. so it tops the red list for lemurs. in the lab at their research station, lemur feces is analysed. behavioral ecologist and sociobiologist dr. claudia fichtel measures levels of stress hormones. raised levels indicate that life is tough for the animals. >> it's also an indicator their health is compromised. just as longterm stress affects the health of humans, it affects the health of lemurs and that in turn is important for their red list entries. it takes a lot of time to >> prepare data for the red list. the scientists here are doing that alongside their own researc