Field Experiments of Tool-Use

Ecological variation influences the appearance and maintenance of tool use in animals, either due to necessity or opportunity, but little is known about the relative importance of these two factors. Here, we combined long-term behavioural data on feeding and travelling with six years of field experiments in a wild chimpanzee community. In the experiments, subjects engaged with natural logs, which contained energetically valuable honey that was only accessible through tool use. Engagement with the experiment was highest after periods of low fruit availability involving more travel between food patches, while instances of actual tool-using were significantly influenced by prior travel effort only. Additionally, combining data from the main chimpanzee study communities across Africa supported this result, insofar as groups with larger travel efforts had larger tool repertoires. Travel thus appears to foster tool use in wild chimpanzees and may also have been a driving force in early hominin technological evolution.

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Cultural innovation and transmission of tool use in wild chimpanzees: evidence from field experiments

Animal Cognition ◽

10.1007/s10071-003-0183-x ◽

2003 ◽

Vol 6 (4) ◽

pp. 213-223 ◽

Cited By ~ 277

Author(s):

Dora Biro ◽

Noriko Inoue-Nakamura ◽

Rikako Tonooka ◽

Gen Yamakoshi ◽

Claudia Sousa ◽

...

Keyword(s):

Tool Use ◽

Field Experiments ◽

Cultural Innovation

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Chimpanzees use tree species with a resonant timbre for accumulative stone throwing

Biology Letters ◽

10.1098/rsbl.2019.0747 ◽

2019 ◽

Vol 15 (12) ◽

pp. 20190747 ◽

Cited By ~ 1

Author(s):

Ammie K. Kalan ◽

Eleonora Carmignani ◽

Richard Kronland-Martinet ◽

Sølvi Ystad ◽

Jacques Chatron ◽

...

Keyword(s):

Tool Use ◽

Tree Species ◽

Field Experiments ◽

Low Frequency ◽

Spectral Energy ◽

Extractive Foraging ◽

Spectral Centroid ◽

Signal Onset ◽

Attack Time ◽

Lower Frequencies

Animals use tools for communication relatively rarely compared to tool use for extractive foraging. We investigated the tool-use behaviour accumulative stone throwing (AST) in wild chimpanzees, who regularly throw rocks at trees, producing impact sounds and resulting in the aggregations of rocks. The function of AST remains unknown but appears to be communication-related. We conducted field experiments to test whether impact sounds produced by throwing rocks at trees varied according to the tree's properties. Specifically, we compared impact sounds of AST and non-AST tree species. We measured three acoustic descriptors related to intrinsic timbre quality, and found that AST tree species produced impact sounds that were less damped, with spectral energy concentrated at lower frequencies compared to non-AST tree species. Buttress roots in particular produced timbres with low-frequency energy (low spectral centroid) and slower signal onset (longer attack time). In summary, chimpanzees use tree species capable of producing more resonant sounds for AST compared to other tree species available.

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Electron Microscopy of the Shape of Small Metal Particles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079024 ◽

1977 ◽

Vol 35 ◽

pp. 300-301

Author(s):

M. Jose Yacaman

Keyword(s):

Electron Microscopy ◽

Metal Particle ◽

Field Experiments ◽

Size Range ◽

Dark Field ◽

Metal Particles ◽

Bragg Condition ◽

Crystal Particle ◽

Small Metal Particle ◽

Small Metal Particles

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.

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