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Coated nuts as an enrichment device to elicit tool use in tufted capuchins ( Cebus apella )
Author(s) -
Visalberghi Elisabetta,
Vitale Augusto F.
Publication year - 1990
Publication title -
zoo biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.5
H-Index - 54
eISSN - 1098-2361
pISSN - 0733-3188
DOI - 10.1002/zoo.1430090108
Subject(s) - biology , nut , significant difference , juvenile , sawdust , horticulture , mathematics , ecology , engineering , statistics , structural engineering
The present paper describes a simple technique that hardens the shell of nuts and makes the use of a tool to crack them open more compelling. Walnuts were coated with a dough of sawdust and nontoxic white glue in different combinations; they were tested for hardness by using machines normally used to test different kinds of wood. Data on relative hardness for uncoated walnuts and walnuts coated with dough of two different combinations are presented. The coated walnuts were significantly harder to break than the uncoated ones, whereas no significant difference was found when comparing the hardness of two types of coated walnuts. Furthermore, observations on a captive group of tufted capuchins ( Cebus apella ) are described. The monkeys needed significantly more time to break open the coated walnuts. Early results show that coated walnuts may favor acquistion of tool use skills in a juvenile capuchin.