Lack of hand preference in wild Hanuman langurs (Presbytis entellus)

• Published in: American journal of physical anthropology Vol. 103; no. 4; pp. 455 - 461
• Main Authors: Mittra, E. S., Fuentes, A., McGrew, W. C.
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.08.1997; Wiley-Liss
• Subjects: Animal ethology; Animals; Biological and medical sciences; Cercopithecidae - psychology; colobines; Feeding Behavior; Female; field study; Functional Laterality; Fundamental and applied biological sciences. Psychology; handedness; laterality; Male; Mammalia; Physical anthropology; Primates; Primatology; Psychology. Psychoanalysis. Psychiatry; Vertebrata; Grooming behavior; Study under natural conditions; Handedness; Vertebrata; Mammalia; Animal activity; Feeding behavior; Primates; Simioidea; Laterality; Animal population; Presbytis entellus
• ISSN: 0002-9483; 1096-8644
• DOI: 10.1002/(SICI)1096-8644(199708)103:4<455::AID-AJPA3>3.0.CO;2-M

Although there is a vast literature on laterality of hand‐use in nonhuman primates, the Colobinae have been notably overlooked. Ten manual activities of differing complexity were studied in five male and five female adult Hanuman langurs (Presbytis entellus) from a well habituated, wild population at Ramnagar, in southern Nepal. The activities recorded were carry, eat, hit, hold, idle, manipulate, reach, retrieve, self‐groom and social groom. This study aimed to examine handedness across tasks and across subjects in a natural population. The overall result was a lack of preference for subjects and patterns. Only in the eating activity did four individuals show significant hand preference, though they were not unidirectional. Eat seemed to be loosely associated with hold due to the requirements of the strata which the monkeys utilize. These results suggest that hand use is unlateralized in P. entellus. Those individuals exhibiting some hand preferences can be viewed as statistical exceptions or perhaps subject to experiential differences. The results are discussed in terms of their evolutionary significance and methodological implications. Am J Phys Anthropol 103:455–461, 1997. © 1997 Wiley‐Liss, Inc.