In Fazenda Boa Vista (Piauí, Brazil) wild bearded capuchins habitually use hammer stones and anvils to access the nutritious endosperm of encased fruit. Capuchins select hammers on the basis of material and weight, and occasionally to crack nuts they transport a stone hammer to an anvil. Nuts, hammer stones and anvils are the necessary resources for the occurrence of tool use. In FBV these resources are not evenly distributed: palm trees and surfaces that can be used as anvils are relatively common, whereas stones heavy and hard enough to serve as ham- mers are quite rare. Hammer stones, anvils and palms co-occur only in the talus and in the cliff-plateau. Here, to assess whether the use of tools reflects resource availability, we analysed the data collected over a 12-months period (1,709 h) concerning the frequency of anvils used for tool use in the different physiognomies and capuchins' daily routes. As expected, tool use (n = 731) was observed most frequently in the talus (69%) and never in the marsh; however, 23% of tool use episodes occurred in the plain (where hammer stones are very rare), and sometime in the cliff (8%). The analysis of the 572 tool use episodes for which GPS coordinates of the anvil used were recorded, showed that they occurred in 109 different anvils (84 in the talus, 13 in the plain, and 12 in the cliff-plateau), and that almost half of the anvils were used more than once. Within the same anvil focal observation, one anvil was used on average by 1.9 individuals (min 1 - max 4) to crack 3.2 nuts (min 2 - max 12). The repeated visits to specific anvil-stone sites and use of a route network to reach them indicate that capuchins know their location and show high anvil-stone site fidelity.
Do wild bearded capuchin monkeys (Cebus libidinosus) select anvils and habitat when use stone tools?
S. Karger,, Basel [etc.] , Svizzera
Folia primatologica (Print) 82 (2011): 345–346.
info:cnr-pdr/source/autori:Spagnoletti, N. ; Visalberghi, E. ; Presotto, A. ; Fragaszy, D.; Izar, P./titolo:Do wild bearded capuchin monkeys (Cebus libidinosus) select anvils and habitat when use stone tools?/doi:/rivista:Folia primatologica (Print)/anno: