Pii: S0006-3207(98)00061-5

We studied the ranging behavior of translocated and non-translocated groups of Alouatta pigra in Belize, Central America from March 1994 to May 1995. Home range size, day-range length and monthly range size were determined for all groups. In high density populations, home range size and day-range length increased with group size. Home range size increased with translocation to a low density population, but day-range length did not, and neither were a€ected by group size. These patterns are consistent with di€erences in the distribution of important food resources in the two areas. The costs of translocation to A. pigra were not revealed by variation in ranging patterns between newly translocated and previously established groups but may be evident in the intensity of range use. Previously established groups use their ranges more intensively than newly translocated groups while the new groups explored the release site and then began to reuse areas explored earlier. Newly translocated groups generally established their home ranges six months after translocation but continued some exploration one year after they were moved. This suggests that a full year of monitoring is not necessarily sucient to determine the size and location of the home ranges of translocated monkeys, but that monitoring should continue through all seasonal phases of food abundance. # 1998 Elsevier Science Ltd. All rights reserved.