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Group-specific archaeological signatures of stone tool use in wild macaques

  1. Lydia V Luncz  Is a corresponding author
  2. Mike Gill
  3. Tomos Proffitt
  4. Magdalena S Svensson
  5. Lars Kulik
  6. Suchinda Malaivijitnond
  1. University of Oxford, United Kingdom
  2. University College London, United Kingdom
  3. Oxford Brookes University, United Kingdom
  4. Max Planck Institute for Evolutionary Anthropology, Germany
  5. Chulalongkorn University, Thailand
Research Advance
Cite this article as: eLife 2019;8:e46961 doi: 10.7554/eLife.46961
9 figures, 2 tables and 2 additional files

Figures

Research site in the Ao Phang Nga National Park, Thailand.

(A) Southeastern tip of Boi Yai Island and (B) Lobi Bay on Yao Noi Island, both within Ao Phang Nga National Park, Southern Thailand.

https://doi.org/10.7554/eLife.46961.002
Stone tools used by wild macaques in Ao Phang Nga National Park to exploit rock oysters (Saccostrea cucullate).

(a) Examples of stone tools used at Lobi Bay. (b) Examples of stone tools used on Boi Yai Island. (c) rock oyster prey species available on both islands and.

https://doi.org/10.7554/eLife.46961.004
Stone tools used by macaques in Ao Phang Nga National Park to exploit Thais bitubercularis.

(a) Examples of stone tools used at Lobi Bay. (b) examples of stone tools used on Boi Yai Island. (c) Thais bitubercularis prey species available on both islands.

https://doi.org/10.7554/eLife.46961.005
Intensity of damage (UWG) compared for stone tools between two sites (Lobi Bay and Boi Yai Island) in the Ao Phang Nga National Park.

The size of the circle indicates the respective number of tools included. (For underlying data, see Source data 1).

https://doi.org/10.7554/eLife.46961.006
Selected tools used to crack open marine prey by wild macaques in Lobi Bay and Boi Yai Island.

(A) Differences in selected tool weight to crack open marine snails. (B) Differences in selected tool weight to crack open Thais bitubercularis. The plots are showing all quantiles and the CIs (grey). (For underlying data, see Source data 1).

https://doi.org/10.7554/eLife.46961.007
Size of marine prey available at Lobi Bay and Boi Yai Island.

The plot is showing the mean with bootstrapped 95% confidence intervals.

https://doi.org/10.7554/eLife.46961.008
Figure 6—source data 1

Maximum length and maximum width of marine snails from Boi Yai Island and Lobi Bay.

https://doi.org/10.7554/eLife.46961.009
Tools selected by wild macaques to crack open oysters at Lobi Bay and Boi Yai Island.

The plot is showing all quantiles and the CIs (grey). (For underlying data, see Source data 1).

https://doi.org/10.7554/eLife.46961.010
Size of oysters available at Lobi Bay and Boi Yai Island.

The plot is showing the mean with bootstrapped 95% confidence intervals.

https://doi.org/10.7554/eLife.46961.011
Figure 8—source data 1

Maximum length and maximum width of oysters on Boi Yai Island and Lobi Bay.

https://doi.org/10.7554/eLife.46961.012
Availability of raw material at Lobi Bay and Boi Yai Island.

(A) Weight of stones available at point transects. (B) Number of availability of stones. The plots show the mean with bootstrapped 95% confidence intervals.

https://doi.org/10.7554/eLife.46961.013
Figure 9—source data 1

Measurements and weight of stones available in the tidal and intertidal zone on Boi Yai Island and Lobi Bay.

https://doi.org/10.7554/eLife.46961.014

Tables

Table 1
Total number of tools associated with specific prey species.
https://doi.org/10.7554/eLife.46961.003
PreyLobi BayBoi Yai Island
Monodonta labio93
Morulla spp.02
Nerita spp.1826
Oysters1026
Thais bitubercularis912
Total limestone hammerstones used4669
Total granite hammerstones used01
Table 2
Grading of use wear by zone (adapted from Haslam et al., 2013)
https://doi.org/10.7554/eLife.46961.015
Use Wear Grade (numerical)Use Wear Grade (descriptive)PittingCrushingFracture
DefinitionDistinct indentations from discrete strikes that can culminate in the creation of more general craters in the stone surfaceRounding and flattening of the tool surface, especially the protruding parts on the points and edges.A breakage of the tool caused by chipping or flaking
Grade 0NoneNo traceNo traceNo trace
Grade 1SlightTrace - minimal and isolated damage. Isolated points of impactTrace - minimal and isolated damageTrace - minimal and isolated fracture
Grade 2MediumOverlapping impact points that have formed a coherent platform of damageSurface clearly damaged but limited evidence of repeated use.Moderate - larger fractureaffecting < 30% of the use zone
Grade 3HighCumulative damage with a pitting to a depth of 2 mmCumulative - rounding can be observed and felt.Extensive - Fracture affecting between 30% and 60% of the use zone
Grade 4Very-HighCratered - a larger more extensive indentation that is more than 2 mm deep and 5 mm in diameter.More progressive rounding that has produced a flatter surface on the use zone.General - fracture extending beyond 60% of the use zone

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files.

Additional files

Transparent reporting form
https://doi.org/10.7554/eLife.46961.016
Source data 1

Measurements and use wear intensity scores of tools collected on Boi Yai Island and Lobi Bay.

Source data for Figures 45 and 7. 

https://doi.org/10.7554/eLife.46961.017

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