Reviewed Article Folia Primatol 1999;70:313–327 Locomotion and Posture in Lagothrix lagotricha Thomas R. Defler Instituto Amazo ´ nico de Investigaciones de la Universidad Nacional de Colombia (IMANI), Leticia, y Estacio ´ n Biolo ´ gica Caparu ´ (Fundacio ´ n Natura), el Vaupés, Colombia Received: October 14, 1998 Accepted after revision: July 15, 1999 Thomas R. Defler Instituto Amazo ´ nico de Investigaciones Universidad Nacional de Colombia A.A. 53200, Bogota ´ (Colombia) Fax +57 9859 27996, E-Mail caparu@impsat.net.co ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 1999 S. Karger AG, Basel 0015–5713/99/0706–0313$17.50/0 Accessible online at: www.karger.com/journals/fpr Key Words Locomotion W Posture W Lagothrix lagotricha W Woolly monkey Abstract This long-term study of woolly monkey (Lagothrix) locomotor and postural behaviour employs methods identical to those used during a previous study of the locomotion and posture of two species of Ateles, allowing a detailed comparison between the two genera, which are strong competitors in extensive parts of the Amazon basin and northern Andes. As in Ateles, Lagothrix locomotion can be divided into five patterns, based on limb usage: quadrupedal walking and running, suspensory locomotion, climbing, bipedalism (very rare in wild woolly monkeys) and leaping. Lagothrix differs from Ateles primarily in its greater reliance on qua- drupedal locomotion during both travel and feeding and on its de-emphasis of the use of suspensory locomotion as compared to Ateles, while the use of climbing and leaping is roughly equal in the two genera. Lagothrix exhibits more generalised (primitive) locomotive behaviour in accordance with its morphology, in comparison to the more specialised Ateles. The generic differences reflect differences in habitat use and particularly foraging ecology. Copyright © 1999 S. Karger AG, Basel Introduction Lagothrix lagotricha [1–4] seems to be a competitor of various Ateles taxa where they are sympatric, and their similar reliance on ripe fruit [1, 5–7] raises the question of what ecological differences they exhibit. Fleagle [8–9] notes that the many ways in