ESSNER, RL: A Comparison of Locomotor Behavior and Habitat Use in Gliding and Nongliding Squirrels

An important component of functional morphological studies is the establishment of ecological relevance. For example, among arboreal animals, it has been demonstrated that differential habitat use among taxa is consistent with morphological variation. Moreover, studies in arboreal taxa have shown that habitat structure can have a strong influence on locomotor behavior. This study quantifies locomotor behavior and habitat use in three North American squirrels: the Southern Flying Squirrel, Glaucomys volans; the Red Squirrel, Tamiasciurus hudsonicus; and the Eastern Chipmunk, Tamias striatus. Trees of varying heights, diameters, and orientations were placed inside an enclosure in order to approximate a natural forest environment. Ten animals from each species were filmed moving in the enclosure and sampled using the bout method of continuous sampling. Flying squirrels glided relatively infrequently compared with other locomotor modes such as climbing, leaping, and running. Red squirrels, which are known to use parachuting locomotion, only did so when attempting to escape recapture. Chipmunks spent considerably more time in trees than expected. The correspondence between locomotor behavior, habitat use, and morphology in these taxa will be discussed.