The spatial ecology of translocated black howler monkeys (Alouatta pigra), in Belize
The ranging behavior, habitat selection, group composition and territoriality of eight groups of black howler monkeys (Alouatta pigra) were compared. Four of the groups were translocated from the Community Baboon Sanctuary (CBS) to the Cockscomb Basin Wildlife Sanctuary (CBWS) during the study, two groups were never translocated and two groups had been moved two years previously. The data were entered into a Geographic Information System (GIS). A new method of estimating the size and shape of a home range using a GIS was developed. Ranging behavior was also examined using a GIS. There were significant differences in day-range length and home range size between the groups in CBS and CBWS that were related to variation in habitat and population density. After one year, translocated monkeys had not fully established their home range although they exhibited similar ranging patterns as groups previously established in the CBWS. However, established groups used their ranges more intensively than newly translocated groups. Home ranges of new and established groups could not be distinguished based upon vegetative differences. All groups in CBWS selected habitats located at low elevations and next to watercourses. These areas were characterized by larger trees and greater relative coverage of food trees. Alouatta pigra was determined to be territorial in CBS but this could not be assessed in CBWS. Variation in population density between sites was found to explain variation in the frequency of inter-group encounters and howling rates. Ano-genital scent-marking was performed by all group members and may help in range advertisement. Face and throat rubbing is performed almost entirely by males, often during inter-group encounters. Population density was also found to influence the social structure of A. pigra groups with single male groups being the predominant social grouping in low density populations and multi-male groups predominating in high density populations.
Ostro, Linde E. T, "The spatial ecology of translocated black howler monkeys (Alouatta pigra), in Belize" (1998). ETD Collection for Fordham University. AAI9825853.