Cathemerality in lemurs

Field studies on Lemuridae have usually focused on daytime activity and largely neglected nocturnal activity, providing a source of bias which may have profoundly affected our understanding of lemur behavior and ecology. Recent field studies have finally provided data collected throughout the 24-hr period, and a complex picture is beginning to emerge. Cathemerality has been described in detail in lemurids inhabiting a variety of habitats, and attempts have been made to assess 1) the proximate role of environmental cues; 2) the functional relevance of cathemerality; and 3) its adaptive value and evolution.