STEVENS, NJ*; WRIGHT, KA; COVERT, HH; NADLER, T; Ohio University College of Osteopathic Medicine; Johns Hopkins Medical School; University of Colorado at Boulder; Endangered Primate Research Center, Cuc Phuong National Park, Vietnam: A comparison of vertebral kinematics of Hatinh and Delacour�s langurs in the Cuc Phuong National Park of Vietnam

Locomotor kinematics of the folivorous primates of Vietnam have until recently been understudied. Research conducted in the Endangered Primate Research Center examined back posture during arboreal quadrupedal locomotion among two similarly sized leaf monkeys, Delacour�s langurs (T. delacouri) and Hatinh langurs (T. laotum hatinhensis). Housed in seminaturalistic enclosures, subjects were filmed walking along horizontal supports approximately 2 inches in diameter. Cameras were positioned in lateral view at a distance sufficient to reduce parallex. Frame rates were optimized to catch rapid movements, and shutter speeds were set to reduce motion blur. Video clips were imported into Peak Motus and kinematic points along the back were digitized at limb touchdown, midsupport and lift off events. Rank-transformed data were analyzed using ANCOVAs with locomotor velocity as the covariate. Results indicate marked differences in back posture between species. In T. laotum hatinhensis, the back remains relatively straight throughout the stride cycle, whereas in T. delacouri, the vertebral column maintains a pronounced flexion. These patterns may reflect locomotor preferences, as Delacour�s langurs appear to engage more frequently in bounding and leaping behaviors than do their congeners. Continued research on postural and locomotor adaptations of these taxa is critical for their conservation and captive management. This research was supported in part by the Zoological Society of San Diego.