... (1959—Sciurinae), and Thorington et al. (2002—Pteromyini). Analysiswas across 8 taxa: Callosciurinae, Ratufinae, Sciurillinae,Sciurinae: Pteromyini, Sciurinae: Sciurini, Xerinae: Marmotini,Xerinae: ... length(Figs. 1E and 1F) are that lactation is short in Marmotini and Protoxerini and long in Pteromyini; for Sciurini (Sciurus) and Pteromyini, heavier species have longer lactation; flyingsquirrels ... squirrels. Flying squirrels are nocturnal,nest in trees, reproduce in trees, and often forage in trees.Flying squirrels are the most adapted for arboreal and glidinglocomotion and temperate forms...